


                                                       COMMON-ISDN-API








                              COMMON ISDN  API





                 Standard Interface between Application Programs
                              and ISDN Adapters


                               Specification






                            Version 1.1, Profile A
                       Date of issue: September 7, 1990






































          COMMON-ISDN-API


                Table of Contents

          1     Introduction ........................................1

          2     Features ............................................1

          3     Overview ............................................2
          3.1   Message queues ......................................3
          3.2   Operations on message queues ........................3
          3.2.1 Registering an application ..........................3
          3.2.2 Messages from the application to the COMMON ISDN API 4
          3.2.3 Messages from the COMMON ISDN API to the application 4
          3.2.4 Releasing an application ............................4
          3.3   General message protocol ............................4
          3.4   Message structure ...................................5
          3.5   Structure of the data area ..........................6
          3.6   Other functions .....................................6
          3.7   Manufacturer-specific expansions ....................6

          4     Messages and functions ..............................7
          4.1   Operations on message queues ........................7
          4.2   Messages ............................................7
          4.3   Other operations ....................................8

          5     Message descriptions ................................9
          5.1   General messages ...................................11
          5.2   Protocol level 2 ...................................36
          5.3   Protocol level 3 ...................................39
          5.4   Telephone service ..................................64
          5.5   Manufacturer-specific messages .....................66
          5.6   Other functions ....................................70
          5.6.1 Manufacturer identification ........................70
          5.6.2 COMMON ISDN API version number .....................70
          5.6.3 COMMON ISDN API serial number ......................70

          6     Flowcharts .........................................71

          Annex A - Implementation with different operating systems
          Annex B  - Profile
























                                                       COMMON-ISDN-API



          1     Introduction

          The COMMON ISDN API enables applications to access ISDN
          adapter boards in a straightforward manner and allows unre-
          stricted use of their functions through a standardized soft-
          ware interface.

          Applications that use this interface will not be affected by
          future expansions or hardware changes. The COMMON ISDN API
          makes the changes transparent to the user application. Futu-
          re expansions that retain compatibility with the existing
          software basis are possible.

          This means that it is possible to link higher-level proto-
          cols and specific ISDN applications to the ISDN via a defi-
          ned, standardized interface, which is supported by different
          ISDN adapter manufacturers. The COMMON ISDN API provides a
          basis for modular applications development in ISDN systems.



          2     Features


          The COMMON ISDN API includes a number of important features.

          1   Support for the basic call features, such as call setup
              and cleardown and display of the caller's ISDN number
          2   Support for several B-channels for voice and/or data
              connections
          3   Support for several logical channels for data links wit-
              hin a physical connection
          4   Possibility of selecting different services and proto-
              cols during connection setup and incoming call
          5   Transparent interface for protocols above Layer 3
          6   Support for one or more S0 bus connections on one or
              more ISDN adapters
          7   Non-operating-system-specific approach for different
              operating systems
          8   Asynchronous mechanism (high throughput)
          9   Defined mechanism for manufacturer-specific expansions
          10  Simple implementation in a minimal configuration with a
              supported ISDN controller
















                                     - 1 -


          COMMON-ISDN-API


          3   Overview


          From its logical viewpoint, the COMMON ISDN API provides a
          connection between any number of application programs (ap-
          plications) and any number of ISDN drivers and ISDN control-
          lers via a standard interface. The applications can be free-
          ly assigned to drivers and controllers. The COMMON ISDN API
          enables both one application to be used for several drivers
          and controllers and several applications to be used for sin-
          gle drivers.

          The applications can use different protocols at different
          protocol levels, the COMMON ISDN API providing the selection
          mechanism needed for this. The COMMON ISDN API also ab-
          stracts from different protocol variants, thus creating a
          standard network access. The basic concept can be adapted to
          both national and international variants. The profile speci-
          fication (see Annex for Profile A) defines the representa-
          tion of data elements in the signaling channel.

          All connection information relevant to the application such
          as charging information, display messages, etc., is availa-
          ble at all times.

          The COMMON ISDN API is an entity. This specification defines
          and standardizes both the entity and the protocol between an
          application and the COMMON ISDN API. The protocol between
          the COMMON ISDN API and the supported drivers is
          manufacturer-specific.

          The COMMON ISDN API covers protocol levels 1 to 3 (physical
          layer, data link layer, network layer) for the B-channel.
          The COMMON ISDN API interface lies above level 3 and thus
          provides the reference point for applications and higher-
          level protocols. The X.75 protocol in accordance with T.90
          is prescribed for layer 2, and implementation in accordance
          with T.70 NL for layer 3. Defined as options are a transpa-
          rent layer 2 and separate access to the protocols T.90 with
          LLC mechanism, ISO 8208 and transparent at level 3, as well
          as support for the telephone service.

          The description below first presents the basic mechanism
          used for the COMMON ISDN API. It is based on message queues
          provided for the exchange of commands and data. The opera-
          tions on these message queues are described, then the struc-
          ture of the exchanged messages is indicated. There follows a
          description of other functions for identification, and the
          mechanism for manufacturer-specific expansions is explained.











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                                                       COMMON-ISDN-API


          3.1  Message queues

          Communication between an application program and the COMMON
          ISDN API takes place via message queues. As diagram 2 shows,
          there is precisely one message queue for the COMMON ISDN API
          itself and for each registered application program. Messages
          are exchanged between the applications programs and the COM-
          MON ISDN API by way of these message queues. For high-volume
          data transfer, the messages are used for indication purposes
          only, and the data is transferred via a data area common to
          the application and the COMMON ISDN API. An exception to
          this is data transfer in the D-channel with the aid of user
          information; in this case the data is directly linked with
          the relevant message. The COMMON ISDN API itself and the
          supported drivers ensure message processing in the order of
          their arrival.

          An application issues commands to an ISDN driver or control-
          ler by placing an appropriate message in the COMMON ISDN API
          message queue. In the reverse direction, a message from an
          ISDN driver or controller is transferred to the message
          queue of the application which it is addressing.

          This method, particularly as used in higher-level protocols
          and multifunctional systems, allows flexible access by seve-
          ral applications to different ISDN drivers and controllers.
          It also provides a powerful mechanism for processing events
          that arrive asynchronously.

          The message queue structure is not specified but is
          manufacturer-dependent and is transparent to the application
          program. The necessary access operations are defined by the
          COMMON ISDN API. The memory needed for an application's mes-
          sage queue is provided by the application.


          3.2   Operations on message queues

          The message queues described represent the link between an
          application and the COMMON ISDN API and the connected ISDN
          drivers and controllers. Only four operations are required
          to use the message queues. The operations on the message
          queues are not restricted to a particular system specifica-
          tion. Their respective characteristics and implementation
          are operating-system-specific.
          At the same time, these operations form the complete inter-
          face which has to be matched to the particular operating sy-
          stem. The four operations are described below.


          3.2.1 Registering an application

          Before an application can issue commands to the COMMON ISDN
          API, it must be registered with the COMMON ISDN API. The API






                                     - 3 -


          COMMON-ISDN-API


          _REGISTER function is used to do this. The COMMON ISDN API
          uses this function to assign a unique system-wide applica-
          tion number (APPL-ID) to the application. In this context,
          system-wide means unique within a network. The message queue
          for the application is set up at the same time. The applica-
          tion makes the storage space needed for this available to
          the COMMON ISDN API.


          3.2.2 Messages from the application to the COMMON ISDN API

          All messages from an application to the COMMON ISDN API are
          put in the message queue of the COMMON ISDN API. The opera-
          tion API_PUT_MESSAGE is provided for this purpose. When this
          operation is used, the application transfers the message. If
          the COMMON ISDN API message queue cannot accept any more
          messages, the operation API_PUT_MESSAGE delivers an error
          value.


          3.2.3 Messages from the COMMON ISDN API to the application

          The COMMON ISDN API manages a message queue for each appli-
          cation; in it, the COMMON ISDN API or the ISDN driver and
          controller put all messages to the application. The opera-
          tion API_GET_MESSAGE is provided for receiving new messages.
          When this operation is used, it returns the received messa-
          ge. If the application does not read out the messages quick-
          ly enough, the queue may overflow. In this case subsequent
          messages from the COMMON ISDN API are lost. The application
          is informed of this error on the next API_GET_MESSAGE opera-
          tion.


          3.2.4 Releasing an application

          After an application has registered, it must always release
          itself from the COMMON ISDN API. This can be done at any
          time with the API_RELEASE operation. Note that when this is
          done the application must clear down all existing connec-
          tions. Releasing the application frees the previously used
          message queue.

          3.3   General message protocol

          Communication between the application and the COMMON ISDN
          API always uses the following general protocol:

          Each message is given a message number. Two different sets
          of numbers are used, depending on the initiator: between
          0x0000 and 0x7FFF in the case of the application and between
          0x8000 and 0xFFFF in the case of the COMMON ISDN API.








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                                                       COMMON-ISDN-API


          When the application sends a request ( _REQ) to the COMMON
          ISDN API, a message number from the application's set of
          numbers is used. The COMMON ISDN API confirms this request
          with a corresponding confirmation (_CONF), using the same
          message number as in the request.

          When a asynchronous event is shown to the application by an
          indication (_IND), a message number from the COMMON ISDN
          API's set of numbers in used. The application replies to the
          indication with the corresponding response (_RESP),
          using the same message number as in the indication.

          Protocol violations by the application that cannot be dis-
          played are ignored.


          3.4   Message structure

          All messages exchanged between the application and the COM-
          MON ISDN API consist of a fixed-length header and a data
          area of variable length. The specified format is used for
          both transfer directions. The data in the message is packed
          in bytes.

               Ŀ
             Message- Message- Message-        Message-
             Header    Daten    Daten           Daten  
               

          The message header has the following structure:

            Ŀ
             Total   APPL-ID  Command  Sub-     Message-
             Length                    command  number  
            


          The meanings are as follows:

          Total length           Word, total length of the message in-
                                 cluding header in bytes
          APPL-ID                Word, identification of the applica-
                                 tion. The APPL_ID assigned to the ap-
                                 plication by the COMMON ISDN API in
                                 the API_REGISTER operation is used.
          Command                Byte, command
          Subcommand             Byte, command subdivision
          Messagenumber          Word, unique number assigned to each
                                 message (see also 3.3)









                                     - 5 -


          3.5   Structure of the data area

          COMMON-ISDN-API


          The data area consists of one, more than one, or no parame-
          ters. A distinction is made between variable and fixed-
          length parameter structures. Hence there exist:

          for variable-length type STRUCT

              Ŀ
               Parameter- Parameter-
                length      data    
              

               Diagram 5: Variable-length parameter coding

          The meanings are as follows:
          Parameter length       Byte, size of data area in bytes
          Parameter data         Byte(s), data area

          and for basic fixed-length types BYTE, WORD and DWORD

              Ŀ
               Parameter-
                 data    
              

               Diagram 6: Parameter coding of basic types


          The arrangement of the basic data types in memory are shown
          in the Annex.

          The number of parameters transferred in a message and their
          data types are defined implicitly by the particular message.
          The maximum length of a message is 180 bytes.


          3.6   Other functions

          Various additional functions, such as manufacturer indica-
          tion, determination of the version number, and a procedure
          for serial numbers, are provided. As this is a local
          function of the COMMON ISDN API, it is called as described
          under message queues under MS-DOS (see below).


          3.7   Manufacturer-specific expansions

          The manufacturer-specific expansions of the COMMON ISDN API
          presented here are possible without altering the basic
          structure. They are identified by an appropriate com-
          mand/subcommand field in the message.










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                                                       COMMON-ISDN-API


          4.    Messages and functions



          4.1   Operations on message queues

          API_REGISTER           - Register an application
          API_RELEASE            - Release an application
          API_PUT_MESSAGE        - Transfer message to the API
          API_GET_MESSAGE        - Fetch message from the API


          4.2 Messages

          CONNECT_REQ            - Set up B-channel connection
          CONNECT_IND            - Indicate a call on the B-channel
          CONNECT_INFO_REQ       - Send further dialing information
          CONNECT_ACTIVE_IND     - Indicate B-channel through-
                                   connected
          DISCONNECT_REQ         - Clear down B-channel connection
          DISCONNECT_IND         - Indicate cleardown on the B-channel
          LISTEN_REQ             - Set the processed service
          GET_PARAMS_REQ         - Request B-channel parameters
          INFO_REQ               - Set the information to be reported
          INFO_IND               - Report B-channel events
          DATA_REQ               - Send data in the D-channel
          DATA_IND               - Receive data in the D-channel
          SELECT_B2_PROTOCOL_REQ - Select level 2 protocol
          SELECT_B3_PROTOCOL_REQ - Select level 3 protocol
          LISTEN_B3_REQ          - Set level 3 processing
          CONNECT_B3_REQ         - Set up level 3 connection
          CONNECT_B3_IND         - Indicate a level 3 connection
          CONNECT_B3_ACTIVE_IND  - Indicate level 3 through-connected
          DISCONNECT_B3_REQ      - Clear down a level 3 connection
          DISCONNECT_B3_IND      - Indicate a level 3 cleardown
          GET_B3_PARAMS_REQ      - Request level 3 parameters
          DATA_B3_REQ            - Send level 3 data
          DATA_B3_IND            - Indicate incoming data
          RESET_REQ              - Reset a connection
          RESET_IND              - Reset indication, connection
          HANDSET_IND            - Reports of handset events
          MANUFACTURER_REQ       - Manufacturer-specific request
          MANUFACTURER_IND       - Manufacturer-specific indication



          List 4.2 only contains the messages that are issued by the
          initiator. The corresponding confirmations and responses are
          not given separately in this list.











                                     - 7 -


          COMMON-ISDN-API


          4.3 Other operations

          API_SET_SIGNAL         - Set signaling function
          API_DEINSTALL          - Remove COMMON ISDN API
          API_GET_MANUFACTURER   - Fetch manufacturer identification
          API_GET_VERSION        - Fetch API version number
          ZPI_GET_SERIAL NUMBER  - Fetch (optional) serial number
          API_MANUFACTURER       - Manufacturer-specific function




















































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                                                       COMMON-ISDN-API


          5     Message descriptions

          The messages exchanged between the application and the COM-
          MON ISDN API are described below. The following basic types
          are converted to the specified message format:

          Type definition:

          BYTE    :=             8-bit parameter, no sign. The sequen-
                                 ce of bits is described in Annex A.
          WORD    :=             16-bit parameter, no sign. The se-
                                 quence of bits is described in Annex
                                 A.
          DWORD   :=             32-bit parameter, no sign. The se-
                                 quence of bits is described in Annex
                                 A.
          STRUCT  :=             Structure (field) with variable
                                 length. The first byte of the field
                                 indicates the length of the field
                                 (cf. Structure of the data area).

                                 Reserved bits in bit fields must be
                                 assigned the value 0.


          Notation

          Hexadecimal values: hexadecimal values are given in the
          standard notation of the programming language C in the form
          0xhh (bytes) and 0xhhhh (words).

          Binary values: binary values are given in the form of a bit
          field followed by a "b". The least significant bit is placed
          on the right.

          Example: 00110010b (binary) is equivalent to 0x32 (hexadeci-
          mal) and corresponds to 50 (decimal).



          Terms and abbreviations used

          Application ID:        Unique system-wide identification of
                                 an application for the COMMON ISDN
                                 API.

          Controller:            A controller is a hardware unit used
                                 to gain access to the ISDN network.
                                 The controller supports none, one, or
                                 more than one data and/or telephone
                                 links. Controllers are numbers in as-
                                 cending order starting at 0.








                                     - 9 -


          COMMON-ISDN-API


          DLPD                   Data Link Protocol Description.
                                 Structure with protocol-dependent ad-
                                 ditional information.

          ff:                    And the following pages

          ffs:                   For further study

          NCCI:                  Network Control Connection Identi-
                                 fier. An NCCI describes a logical
                                 connection on level 3. If the appro-
                                 priate protocol is implemented in the
                                 COMMON ISDN API, selection of a mul-
                                 tiplexed level 3 is possible. This
                                 allows several NCCIs


          NCPD:                  Network Control Protocol Description.
                                 Structure with protocol-dependent ad-
                                 ditional information.

          NCPI:                  Network Control Protocol Information.
                                 Protocol-dependent additional infor-
                                 mation about a network connection.


          PLCI:                  Physical Link Connection Identifier.
                                 A PLCI describes a physical connec-
                                 tion between two users. It is supp-
                                 lied by the COMMON ISDN API on initi-
                                 ation of connection setup. A PLCI in-
                                 itially describes a signaling link.
                                 When activated, the signaling channel
                                 is assigned a physical channel. A
                                 PCLI is always linked to a controller
                                 and an application program.
























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                                                       COMMON-ISDN-API


          5.1   General messages


          CONNECT_REQ - Set up B-channel connection

          Description
          This messages initiates setup of a physical B-channel link
          to the stipulated destination address (destination address
          as per profile A). The B-channel parameter (coding as per
          profile A) can be used to specify the desired B-channel.
          The info mask is used to stipulate which of the W elements
          are to be displayed in the message INFO_IND.
          The parameter source EAZ (EAZ corresponds to profile A) in-
          dicates the EAZ of the initiator.
          The parameter outgoing service and outgoing service add in-
          dicate the service to be used in accordance with profile A.

          Message
          Command/subcommand:    0x02 / 0x00

                                 BYTE    Controller
                                 BYTE    B-channel
                                 DWORD   Info mask
                                 BYTE    Outgoing service
                                 BYTE    Outgoing service add.
                                 BYTE    Source EAZ
                                 STRUCT  Destination address

          Parameters
          Controller             Transparent (can be set in applica-
                                 tion)
          B-channel              Bit field, channel identification as
                                 per profile A
          Info mask              Bit field with following coding:
                                 [0]     Charging information
                                 [1]     Date
                                 [2]     Display
                                 [3]     User-user information
                                 [4]     Cause
                                 [5]     Status of called party
                                 [6 to 31]       Reserved
          Outgoing service       Service indicator as per profile A
          Outgoing service add.  Additional info as per profile A
          Source EAZ             EAZ as per profile A
          Destination address    Destination address as per profile A

          Note
          The info mask bit field specifies which W elements are to
          trigger an INFO_IND when they are received











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          COMMON-ISDN-API


          CONNECT_CONF


          Description
          This message confirms the initiation of call setup. This
          connection is thus assigned a PLCI which serves as an iden-
          tifier in further processing. Any errors are returned to the
          parameter info.

          Message
          Command/subcommand:    0x02 / 0x01

                                 WORD    PLCI
                                 WORD    Info

          Parameter
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Info                   0:      Connect initiated
                                 0x2001  Incorrect controller
                                 0x3101  B-channel incorrectly coded
                                 0x3102  Info mask incorrectly coded

          Note
          The connection is in the setup phase at this point in time.
          Subsequent switching is indicated by the message CONNECT_AC-
          TIVE_IND.

































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                                                       COMMON-ISDN-API


          CONNECT_IND - Indicate an incoming call on the B-channel


          Description
          This message indicates the request for call setup from a re-
          mote station. At this point the call is in the setup phase,
          no physical connection having been established yet. Subse-
          quent switching of the B-channel is indicated by the message
          CONNECT_ACTIVE_IND

          For the incoming call, a PLCI is assigned which can be used
          to identify and activate the call in the following. The ad-
          dresses and the wanted service are indicated by the parame-
          ters caller address, requested EAZ, requested service and
          requested service add

          Message
          Command/subcommand:    0x02 / 0x02

                                 WORD    PLCI
                                 BYTE    Controller
                                 BYTE    Requested service
                                 BYTE    Requested service add
                                 BYTE    Requested EAZ
                                 STRUCT  Caller address

          Parameter
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Controller             Transparent
          Requested service      Service indicator as per profile A
          Req. service a.        Additional info as per profile A
          Requested EAZ          EAZ as per profile A
          Caller address         Caller address as per profile A


          Note
          To activate the signaling of incoming calls, the message LI-
          STEN_REQ must be sent beforehand for each controller to be
          used.




















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          COMMON-ISDN-API


          CONNECT_RESP


          Description
          This message is used to accept or reject an incoming call
          for the application. The incoming call is identified via pa-
          rameter PLCI. The parameter reject is used to accept or re-
          ject the call. A value unequal to 0 is treated as the cause
          as per profile A.

          Message
          Command/subcommand:    0x02 / 0x03

                                 WORD    PLCI
                                 BYTE    Reject

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Connect                0:      Accept call
                                 <>0:    Reject call, value
                                         reserved (cause)






































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                                                       COMMON-ISDN-API


          CONNECT_INFO_REQ - Transmit further dialing information


          Description
          This message permits overlap sending. It can be used repea-
          tedly following a CONNECT_REQ up to indication of the con-
          cluding message CONNECT_ACTIVE_IND.

          Message
          Command/subcommand:    0x03 / 0x02
                                 WORD    PLCI
                                 STRUCT  Destination address

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Destination address    Destination address as per profile A

          Note
          For teletex and fax services, this message may not be used,
          since block dialing is prescribed for these services.







































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          COMMON-ISDN-API


          CONNECT_INFO_CONF


          Description
          This message confirms acceptance of CONNECT_INFO_REQ.

          Message
          Command/subcommand:    0x09 / 0x01
                                 WORD    PLCI
                                 WORD    Info

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Info                   0:      Initiates transmission of
                                         dialing information
                                 0x2002  Incorrect PLCI











































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                                                       COMMON-ISDN-API


          CONNECT_ACTIVE_IND - Indicate, B-channel switched through


          Description
          This message indicates the switching through of a B-channel.
          The  connection that is identified via the PLCI is thus set
          up correctly. The address of the far-end station is notified
          in the parameter connected address.


          Message
          Command/subcommand:    0x03 / 0x02
                                 WORD    PLCI
                                 STRUCT  Connected address

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Connected address      Connected address as per profile A









































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          COMMON-ISDN-API


          CONNECT_ACTIVE_RESP


          Description
          With this message, the application confirms notification of
          the switching of a B-channel.

          Message
          Command/subcommand:    0x03 / 0x03
                                 WORD    PLCI

          Parameter
          PLCI                   Physical Link Connection Identifier,
                                 transparent

          Note
          This message has no function.











































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                                                       COMMON-ISDN-API




          DISCONNECT_REQ - Clear down B-channel connection


          Description
          This message initiates cleardown of a B-channel. The B-
          channel is identified via the stipulated PLCI. The parameter
          cause can be used to indicate a cause of cleardown (coding
          as per profile A).

          Message
          Command/subcommand:    0x04 / 0x00
                                 WORD    PLCI
                                 BYTE    Cause


          Parameter
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Cause                  Cause as per profile A (user to
                                 network)


          Note
          If there are level 3 connections on the activated B-channel
          at this stage, cleardown of all level 3 connections set up
          on the B-channel is indicated via the appropriate
          B3_DISCONNECT_IND.
          Cleardown of the B-channel is then started.






























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          COMMON-ISDN-API


          DISCONNECT_CONF


          Description
          This message confirms the initiation of cleardown of a B-
          channel. Any faults are coded in the parameter info.

          Message
          Command/subcommand:    0x04 / 0x01
                                 WORD    PLCI
                                 BYTE    Info

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Info                   0:      Disconnect initiated
                                 0x2002  Incorrect PLCI











































                                     - 20 -


                                                       COMMON-ISDN-API


          DISCONNECT_IND - Indicate a cleardown on the B-channel


          Description
          This message indicates cleardown of the B channel. The B-
          channel is identified via the stipulated PLCI. The parameter
          info indicates a reason.

          Message
          Command/subcommand:    0x04 / 0x02
                                 WORD    PLCI
                                 WORD    Info

          Parameter
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Info                   0x3301  Error on setup of D-channel,
                                         level 1
                                 0x3302  Error on setup of D-channel,
                                         level 2
                                 0x3305  Abort D-channel, level 1
                                 0x3306  Abort D-channel, level 2
                                 0x3307  Abort D-channel, level 3
                                 0x34xx  Abort by network. The cause
                                         is coded in xx as per profile
                                         A.


































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          COMMON-ISDN-API


          DISCONNECT_RESP


          Description
          With this message, the application confirms cleardown of the
          B-channel.

          Message
          Command/subcommand:    0x04 / 0x03
                                 WORD    PLCI

          Parameter
          PLCI                   Physical Link Connection Identifier,
                                 transparent

          Note
          With this message the PLCI is enabled.











































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                                                       COMMON-ISDN-API


          LISTEN_REQ - Set services


          Description
          As preset, incoming calls are not notified to an applica-
          tion. The message LISTEN_REQ can be used to select which of
          the incoming calls should be indicated to the application
          via the message CONNECT_IND.

          The selection is made according to two criteria. The parame-
          ter serviced EAZ mask allows the application to select which
          EAZ(s) are to be processed. The reaction is possible on one,
          several, or all of the EAZs.

          The parameter serviced SI mask allows the application to se-
          lect which of the services identified via the associated
          service indicators are to be processed.

          The W elements to be notified are preset via the info mask
          for the treatment of incoming calls. The preset applies to
          all calls received via the stipulated controller.

          The message LISTEN_REQ can be used as often as required. The
          final setting always applies to each application. If inco-
          ming calls are not to be notified, the parameters serviced
          EAZ mask and serviced SI mask must be set to 0.

          Mesage
          Command/subcommand:    0x05 / 0x00
                                 BYTE    Controller
                                 DWORD   Info mask
                                 WORD    Serviced EAZ mask
                                 WORD    Serviced SI mask
          Parameters
          Controller             Transparent (can be set in applica-
                                 tion)
          Info mask              Bit field, coding as follows:
                                 [0]     Charging information
                                 [1]     Date
                                 [2]     Display
                                 [3]     User-user information
                                 [4]     Cause
                                 [5]     Status of called party
                                 [6 to 31]       Reserved
          Serviced EAZ mask      Bit field [0 to 9] to indicate which
                                 EAZs can be serviced; the bit number
                                 corresponds to the EAZ. Bit number 0
                                 is for a global call. Several EAZs
                                 can be serviced by one application.
                                 The serviced EAZ mask parameter has
                                 the following codings:

                                 Response to global call only







                                     - 23 -


          COMMON-ISDN-API


                                 000000001b
                                 Response to precisely one EAZ
                                 000000010b to 100000000b
                                 Response to global call and precisely
                                 one EAZ
                                 000000011b to 100000001b
                                 Response to global call and all EAZs
                                 1111111111b

          Serviced SI mask       Bit field [0 to 15] to indicate which
                                 services can be operated. One appli-
                                 cation can serve several services.
                                 The bit numbers are coded as follows:

                                 [0]     Videophone
                                 [1]     Telephony
                                 [2]     a/b services
                                 [3]     X.21 services
                                 [4]     Fax (Group 4)
                                 [5]     Videotex (64 kbit/s)
                                 [6]     -
                                 [7]     Data transmission (64 kbit/s)
                                 [8]     X.25 services
                                 [9]     Teletex 64
                                 [10]    Mixed mode
                                 [11]    -
                                 [12]    -
                                 [13]    Remote control
                                 [14]    Graphic telephone service
                                 [15]    Videotex (new standard)

                                 The additional byte in the service
                                 indicator (see profile A) is not eva-
                                 luated and is forwarded transparently
                                 to the application.

          Note
          The info mask bit field specifies which W elements are to
          trigger an INFO_IND when they are received.





















                                     - 24 -


                                                       COMMON-ISDN-API


          LISTEN_CONF


          Description
          This message confirms the preset for the treatment of inco-
          ming calls. Any errors are coded in the parameter info.


          Message
          Command/subcommand:    0x05 / 0x01
                                 BYTE    Controller
                                 WORD    Info

          Parameter
          Controller             Transparent (can be set in applica-
                                 tion)
          Info                   0:      Listen is active
                                 0x2001  Incorrect controller
                                 0x3102  Info mask incorrectly coded
                                 0x3103  Serviced EAZ mask incorrectly
                                         coded
                                 0x3104  Serviced SI mask incorrectly
                                         coded
                                 0x3202  Conflict between registra-
                                         ations



































                                     - 25 -


          COMMON-ISDN-API


          GET_PARAMS_REQ - Request B-channel parameters


          Description
          This message can be used to determine the values of various
          parameters of a B-channel connection. The B-channel connec-
          tion is identified by the specified PLCI.

          Message
          Command/subcommand:    0x06 / 0x00
                                 WORD    PLCI

          Parameter
          PLCI                   Physical Link Connection Identifier,
                                 transparent













































                                     - 26 -


                                                       COMMON-ISDN-API


          GET_PARAMS_CONF


          Description
          This message returns the current parameters of a B-channel
          connection. The parameter B3 link count contains the number
          of level 3 connections on this physical B-channel connec-
          tion. The meaning of the other parameters is described in
          the message CONNECT_REQ or CONNECT_ACTIVE_IND.

          Message
          Command/subcommand:    0x06 / 0x01
                                 WORD    PLCI
                                 BYTE    Controller
                                 BYTE    B-channel
                                 WORD    Info
                                 BYTE    B3 link count
                                 BYTE    Service
                                 BYTE    Service add
                                 BYTE    Serviced EAZ
                                 STRUCT  Connected address
          Parameters
          PLCI                   Physical Link Connection Identifier,
          Controller             transparent (can be set in applica-
                                 tion)
          B-channel              Bit field, channel identification as
                                 per profile A
          Info                   0:      Parameter value valid
                                 0x2002  Incorrect PLCI
                                 0x3204  PLCI not active
          B3 link count          Number of B3 connections currently
                                 being handled via this B link
          Service                Service indicator as per profile A
          Service add            Additional info as per profile A
          Serviced EAZ           EAZ as per profile A
          Connected address      Connected address as per profile A
























                                     - 27 -


          COMMON-ISDN-API


          INFO_REQ - Set the B-channel information to be reported


          Description
          This message sets the W elements relating to the B-channel
          that are to notified to the application. The individual W
          elements are stipulated via the parameter info mask. The pa-
          rameter PLCI identifies the B-channel connection.

          An INFO_REQ can be used as often as required during a con-
          nection. The last stipulated info mask always applies. The
          indication of W elements can be disabled by an info mask
          with the value 0.

          Message
          Command/subcommand:    0x07 / 0x00
                                 WORD    PLCI
                                 DWORD   Info mask

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Info mask              Bit field, coding as follows:
                                 [0]     Charging information
                                 [1]     Date
                                 [2]     Display
                                 [3]     User-user information
                                 [4]     Cause
                                 [5]     Status of called party
                                 [6 to 31]       Reserved

          Note
          The info mask bit field specifies which W elements are to
          trigger an INFO_IND when they are received.


























                                     - 28 -


                                                       COMMON-ISDN-API


          INFO_CONF


          Description
          This message confirms the setting of the W elements to be
          reported. Any errors are coded in the parameter info.

          Message
          Command/subcommand:    0x07 / 0x01
                                 WORD      PLCI
                                 BYTE      Info

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Info                   0:        W elements selected
                                 0x2002    Incorrect PLCI
                                 0x3102    Info mask incorrectly coded










































                                     - 29 -


          COMMON-ISDN-API


          INFO_IND - Report B-channel events


          Description
          This message indicates an event for a B-channel as expressed
          by a W element (info element). The B-channel connection is
          identified via the stipulated PLCI. The reported W element
          is identified via the parameter info number (coding as per
          profile A). The value of the W element is indicated in the
          parameter info element (coding as per profile A).

          Message
          Command/Subcommand:    0x07 / 0x02
                                 WORD      PLCI
                                 WORD      Info number
                                 STRUCT    Info element

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Info number            Identification of the W element as
                                 per profile A
          Info element           W-element-dependent structure

          Note
          An individual INFO_IND is displayed for each W element.


































                                     - 30 -


                                                       COMMON-ISDN-API


          INFO_RESP


          Description
          With this message the application confirms the receipt of an
          INFO_IND.

          Message
          Command/Subcommand:    0x07 / 0x03
                                 WORD      PLCI

          Parameter
          PLCI                   Physical Link Connection Identifier,
                                 transparent

          Note
          This message has no function.











































                                     - 31 -


          COMMON-ISDN-API


          DATA_REQ - Send data in the D-channel with USER-INFO messa-
          ges


          Description
          This message can be used to transmit date in the form of
          user-user information. The B-channel is identified via the
          PLCI. The data to be transmitted is stipulated in a data
          structure.

          Message
          Command/subcommand:    0x08 / 0x00
                                 WORD      PLCI
                                 STRUCT    User data

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          User data              User-user information as per profile
                                 A

          Note
          This function is not supported in all networks.





































                                     - 32 -


                                                       COMMON-ISDN-API


          DATA_CONF


          Description
          This message confirms acceptance of the DATA_REQ. Any errors
          are coded in the parameter info.

          Message
          Command/subcommand:    0x08 / 0x01
                                 WORD      PLCI
                                 WORD      Info

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Info                   0:        Transmission of user infor-
                                           mation initiated
                                 0x2002    Incorrect PLCI
                                 0x3203    Function is not supported
                                 0x3204    PLCI not active








































                                     - 33 -


          COMMON-ISDN-API


          DATA_IND - Receive data in the D-channel via USER-INFO mes-
          sages


          Description
          This message displays incoming data transmitted in the form
          of user-user information. The B-channel connection is iden-
          tified via the PLCI. The incoming data is supplied in a user
          data structure.

          Message
          Command/subcommand:    0x08 / 0x02
                                 WORD      PLCI
                                 STRUCT    User data

          Parameter
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          User Data              User-user information as per profile
                                 A

          Note
          This function is not supported in all networks.





































                                     - 34 -


                                                       COMMON-ISDN-API


          DATA_RESP


          Description
          With this message the application confirms receipt of a DA-
          TA_IND.

          Message
          Command/subcommand:    0x08 / 0x03
                                 WORD      PLCI

          Parameter
          PLCI                   Physical Link Connection Identifier,
                                 transparent

          Note
          This message has no function.











































                                     - 35 -


          COMMON-ISDN-API


          5.2   Protocol level 2


          SELECT_B2_PROTOCOL_REQ - Select level 2 protocol


          Description
          This message selects the level 2 protocol to be used. The B-
          channel connection is identified via the PLCI parameter. The
          protocol is identified  via the B2 protocol. If protocol se-
          lection is not performed for a PLCI, the preset is adopted.
          Additional protocol-independent information can be set via
          the parameter DLPD.

          Message
          Command/subcommand:    0x40 / 0x00
                                 WORD      PLCI
                                 BYTE      B2 protocol
                                 STRUCT    DLPD

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          B2 protocol            Protocol identification:
                                 0x01      X.75 SLP basic operation
                                           mode, with implementation
                                           rules as per T.90 (default)
                                 0x02      Transparent HDLC with bit
                                           stuffing, frame detection
                                           and CRC check
                                 0x03      Bit transparent
                                 0x04      SNA-SDLC
                                 0x05      X.75 Vtx
                                 0x..      Reserved
          DLPD                   Data Link Protocol Description
                                 structure with the following additio-
                                 nal information:
                                 WORD      Data length
                                 BYTE      Link address A
                                 BYTE      Link address B
                                 BYTE      Module mode
                                 BYTE      Window size
                                 STRUCT    XID

          Data length            Max. length of a level 2 information
                                 field
          Link address A         Link address A
          Link address B         Link address B
          Modulo mode            8:        Modulo 8
                                 128:      Modulo 128
          Window size            Window size
          XID                    Structure for XID information in SNA
                                 protocol







                                     - 36 -


                                                       COMMON-ISDN-API



          Preset for different level 2 protocols:

          B2 protocol            0x01   0x02  0x03  0x04   0x05

          Data length            130    512   512   262    130
          Link address A         0x03   N/A   N/A   0xC1   0x03
          Link address B         0x01   N/A   N/A   N/A    0x01
          Modulo mode            8      N/A   N/A   8      8
          Window size            7      N/A   N/A   7      7
          XID                    N/A    N/A   N/A   *      N/A

          *:    Structure of length 0
          N/A   not applicable

          Note
          If SELECT_B2_PROTOCOL_REQ is not called, the preset protocol
          X.75  is adopted. The structure DLPD with length 0 selects
          the preset of the selected level 2 protocol. Initialization
          and processing of level 2 is performed implicitly together
          with the messages of level 3.

          The X.75 protocol stipulated for this protocol level must be
          supported by all COMMON ISDN API implementations, together
          with the associated preset values of the DLPD. The data
          length can be set up to 2048 bytes. If further protocols are
          supported on level 2 by the particular implementat-ion, the
          associated preset values of the DLPD must also be supported.
































                                     - 37 -


          COMMON-ISDN-API


          SELECT_B2_PROTOCOL_CONF


          Description
          This message confirms the protocol setting. Any errors are
          coded in the parameter info.

          Message
          Command/subcommand:    0x40 / 0x01
                                 WORD      PLCI
                                 WORD      Info

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Info                   0:        Protocol selected
                                 0x2002    Incorrect PLCI
                                 0x3105    B2 protocol incorrect
                                 0x3106    DLPD incorrect
                                 0x3206    B2 protocol is not suppor-
                                           ted
                                 0x3207    Changeover of B2 protocol
                                           not possible in this state
                                 0x320A    Parameters used not suppor-
                                           ted in DLPD



































                                     - 38 -


                                                       COMMON-ISDN-API


          5.3 Protocol level 3


          SELECT_B3_PROTOCOL_REQ - Select level 3 protocol


          Description
          With this message it is possible to select the level 3 pro-
          tocol to be used. The B-channel connection is identified by
          way of the parameter PLCI. The protocol is selected by sti-
          pulating the B3 protocol. If no protocol is selected for a
          PLCI, the preset value is adopted. The parameter NCPD can be
          used to set additional protocol-independent information.

          Message
          Command/subcommand:    0x80 / 0x00
                                 WORD      PLCI
                                 BYTE      B3 protocol
                                 STRUCT    NCPD

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          B3 protocol            Protocol identification:
                                 0x01      T70 NL for line switching
                                           (CSPDN) (default)
                                 0x02      ISO 8208 (DTE/DTE)
                                 0x03      Level 3 as per T.90, Appen-
                                           dix II
                                 0x04      Transparent
                                 0x..      Reserved
          NCPD                   Network control protocol description
                                 with protocol-dependent additional
                                 information:
                                 WORD      LIC
                                 WORD      HIC
                                 WORD      LTC
                                 WORD      HTC
                                 WORD      LOC
                                 WORD      HOC
                                 BYTE      Modulo mode

          LIC                    ffs.
          HIC                    ffs.
          LTC                    ffs.
          HTC                    ffs.
          LOC                    ffs.
          HOC                    ffs.
          Modulo mode            8:        Modulo 8
                                 128:      Modulo 128

          Preset for different level 3 protocols:








                                     - 39 -


          COMMON-ISDN-API


          B3 protocol            0x01   0x02   0x03   0x04

          LIC                    130    512    512    262
          HIC                    N/A    ffs.   ffs.   N/A
          LTC                    N/A    ffs.   ffs.   N/A
          LTC                    N/A    ffs.   ffs.   N/A
          LOC                    N/A    ffs.   ffs.   N/A
          HOC                    N/A    ffs.   ffs.   N/A
          Modulo mode            8      ffs.   ffs.   8

          N/A  not applicable

          Note
          The preset protocol T70 NL is used without calling SE-
          LECT_B3_PROTOCOL_REQ. The structure NCPD with length 0 se-
          lects the preset value of the selected level 3 protocol. For
          transparent level 3, activation, deactivation and the ex-
          change of data is performed with level 2 via the correspon-
          ding level 3 operations.

          The parameter NCPI used in the messages CONNECT_B3_REQ, CON-
          NECT_B3_IND, CONNECT_B3_RESP, CONNECT_B3_ACTIVE_IND, DISCON-
          NECT_B3_REQ and DISCONNECT_B3_IND has no meaning for the T70
          NL and transparent protocols and is transferred as a struc-
          ture with length 0. If the ISO 8208 protocols or level 3 as
          per T.90 are selected, the parameter NCPI contains the con-
          tents of  the X.25 PLP packets according to the packet type.

          The reset procedure varies according to the protocol set.
          For protocols T70 NL, ISO 8208 and T.90, the reset procedure
          in executed in accordance with the protocol recommendations.
          For the transparent protocol, a RESET_B3_REQ is answered
          with a successful RESET_B3_CONF without further consequen-
          ces.

          The T70 NL protocol stipulated as preset for this protocol
          level must be supported with the associated preset values of
          the NCPD by all COMMON ISDN API implementations. If further
          protocols are implemented on level 3 by the particular ap-
          plication, the associated preset values of the NCPD must
          also be supported.



















                                     - 40 -


                                                       COMMON-ISDN-API


          SELECT_B3_PROTOCOL_CONF


          Description
          This message confirms the protocol setting. Any errors are
          coded in the parameter info.

          Message
          Command/subcommand:    0x81 / 0x01
                                 WORD      PLCI
                                 WORD      Info

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Info                   0:        Protocol selected
                                 0x2002    Incorrect PLCI
                                 0x3107    B3 protocol incorrect
                                 0x3108    NCPD incorrect
                                 0x3208    B3 protocol is not suppor-
                                           ted
                                 0x3209    Changeover of B3 protocol
                                           in this state not possible
                                 0x320B    Parameters used in NCPD are
                                           not supported



































                                     - 41 -


          COMMON-ISDN-API


          LISTEN_B3_REQ - Set up level 3 connection


          Description
          As preset, incoming calls on level 3 of an application are
          not reported.
          The message LISTEN_B3_REQ can be used to report incoming
          calls on level 3.

          The B-channel connection is identified via the PLCI. A LI-
          STEN_B3_REQ can thus be sent only when a PLCI is available.
          There are no other restrictions for the time at which this
          message can be sent to the API.

          The effect of the LISTEN_B3_REQ is not cancelled until the
          associated PLCI becomes invalid, i.e until the layer 1 con-
          nection in the network is cleared down.

          Message
          Command/subcommand:    0x81 / 0x00
                                 WORD      PLCI

          Parameter
          PLCI                   Physical Link Connection Identifier,
                                 transparent



































                                     - 42 -


                                                       COMMON-ISDN-API


          LISTEN_B3_CONF


          Description
          This message confirms the preset value for treatment of in-
          coming calls on level 3. Any errors are coded in the parame-
          ter Info.

          Message
          Command/subcommand:    0x81 / 0x01
                                 WORD      PLCI
                                 WORD      Info

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Info                   0:        Listen is active
                                 0x2002    Incorrect PLCI










































                                     - 43 -


          COMMON-ISDN-API


          CONNECT_B3_REQ - Setup of the level 3 connection


          Description
          This message initiates the setup of a level 3 connection.
          The B-channel connection is identified via the parameter
          PLCI. Additional protocol-dependent information can be
          transferred with the parameter NCPI.

          Message
          Command/subcommand:    0x82 / 0x00
                                 WORD      PLCI
                                 STRUCT    NCPI

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          NCPI                   Network control protocol information,
                                 structure with additional protocol-
                                 dependent information.

          Note
          The meaning of the parameter NCPI depends on the protocol
          used. See SELECT_B3_PROTOCOL_REQ.




































                                     - 44 -


                                                       COMMON-ISDN-API


          CONNECT_B3_CONF


          Description
          With this message the initiation of a level 3 connection se-
          tup is confirmed. This connection is thus assigned an NCCI,
          by way of which it is subsequently identified. Any errors
          are supplied in the parameter info.



          Message
          Command/subcommand:    0x82 / 0x01
                                 WORD      PLCI
                                 WORD      NCCI
                                 WORD      Info

          Parameters
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          NCCI                   Network Control Connection Identi-
                                 fier, transparent
          Info                   0:        Connect initiated
                                 0x2002    Incorrect PLCI
                                 0x3109    NCPI incorrect
                                 0x3204    PLCI not active
                                 0x320C    Parameters used not suppor-
                                           ted in NCPI

          Note
          The connection is in the setup phase at this stage. The
          switching is indicated later by the message CON-
          NECT_B3_ACTIVE_IND.



























                                     - 45 -


          COMMON-ISDN-API


          CONNECT_B3_IND - Indicate an incoming level 3 connection


          Description
          This message displays an incoming call for a level 3 connec-
          tion. At this point in the message the connection is in the
          setup phase. The subsequent switching is indicated by the
          message CONNECT_B3_ACTIVE_IND.

          For the incoming call an NCCI is assigned, by way of which
          this call is subsequently identified and can be addressed.
          Additional protocol-dependent information can be transferred
          with parameter NCPI.
          To activate the reporting of incoming calls, the message LI-
          STEN_B3_REQ must first be sent for each PLCI to be used.


          Message
          Command/subcommand:    0x82 / 0x02
                                 WORD      NCCI
                                 WORD      PLCI
                                 STRUCT    NCPI

          Parameters
          NCCI                   Network Control Connection
                                 Identifier, transparent
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          NCPI                   Network Control Protocol Information,
                                 structure with protocol-dependent ad-
                                 ditional information
          Note
          The meaning of the parameter NCPI depends on the protocol
          used. See SELECT_B3_PROTOCOL_REQ.


























                                     - 46 -


                                                       COMMON-ISDN-API


          CONNECT_B3_RESP


          Description
          With this message, the application accepts or rejects an in-
          coming call on level 3. The incoming call is identified via
          the parameter NCCI. The call can be accepted or rejected via
          the parameter reject. The parameter NCPI can be used to
          transfer additional protocol-dependent information.

          Message
          Command/subcommand:    0x82 / 0x03
                                 WORD      NCCI
                                 BYTE      Reject
                                 STRUCT    NCPI

          Parameter
          NCCI                   Network Control Connection
                                 Identifier, transparent
          NCPI                   Network Control Protocol Information,
                                 structure with protocol-dependent ad-
                                 ditional information.
          Reject                 0:        Accept call
                                 <>0:      Reject call

          Note
          The meaning of the parameter NCPI depends on the protocol
          used. See SELECT_B3_PROTOCOL_REQ.
































                                     - 47 -


          COMMON-ISDN-API


          CONNECT_B3_ACTIVE_IND - Indicate B-channel level 3 is active


          Description
          This message displays the switching of the level 3 connec-
          tion. The connection is identified via the parameter NCCI.
          The parameter NCPI can be used to transfer additional
          protocol-dependent information.

          Message
          Command/subcommand:    0x83 / 0x02
                                 WORD      NCCI
                                 STRUCT    NCPI

          Parameters
          NCCI                   Network Control Connection
                                 Identifier, transparent
          NCPI                   Network Control Protocol Information,
                                 structure with protocol-dependent ad-
                                 ditional information.

          Note
          The meaning of the parameter NCPI depends on the protocol
          used. See SELECT_B3_PROTOCOL_REQ.




































                                     - 48 -


                                                       COMMON-ISDN-API


          CONNECT_B3_ACTIVE_RESP


          Description
          With this message the application confirms the switching of
          a level 3 connection.

          Message
          Command/subcommand:    0x83 / 0x03
                                 WORD      NCCI

          Parameter
          NCCI                   Network Control Connection
                                 Identifier, transparent

          Note
          This message has no function.











































                                     - 49 -


          COMMON-ISDN-API


          DISCONNECT_B3_REQ - Clear down a level 3 connection


          Description
          This message initiates the cleardown of a level 3 connec-
          tion. The connection is identified via the NCCI stipulated.
          The parameter NCPI can be used to transfer additional
          protocol-dependent information.


          Message
          Command/subcommand:    0x84 / 0x00
                                 WORD      NCCI
                                 STRUCT    NCPI

          Parameters
          NCCI                   Network Control Connection
                                 Identifier, transparent
          NCPI                   Network Control Protocol Information,
                                 structure with additional protocol-
                                 dependent information.

          Note
          The meaning of the parameter NCPI  depends on the protocol
          used. See SELECT_B3_PROTOCOL_REQ.



































                                     - 50 -


                                                       COMMON-ISDN-API


          DISCONNECT_B3_CONF


          Description
          With this message the initiation of the connection setup is
          confirmed. Any errors are coded in the parameter info.


          Message
          Command/subcommand:    0x84 / 0x01
                                 WORD      NCCI
                                 WORD      Info

          Parameters
          NCCI                   Network Control Connection
                                 Identifier, transparent
          Info                   0:        Disconnect initiated
                                 0x2003    Incorrect NCCI
                                 0x3109    NCPI incorrect
                                 0x320C    Parameters used in NCPI not
                                           supported

          DISCONNECT_B3_IND - Indicate cleardown of a level 3 connec-
          tion


          Description
          This message displays the cleardown of a level 3 connection.
          The connection is identified via the stipulated NCCI. The
          parameter NCPI can be used to transfer additional protocol-
          dependent information.

          Message
          Command/subcommand:    0x84 / 0x02
                                 WORD      NCCI
                                 WORD      Info
                                 STRUCT    NCPI

          Parameters
          NCCI                   Network Control Connection
                                 Identifier, transparent
          Info                   0x3303    Error during setup of B-
                                           channel level 1
                                 0x3304    Error during setup of B-
                                           channel level 2
                                 0x3308    Abort B-channel level 1
                                 0x3309    Abort B-channel level 2
                                 0x330A    Abort B-channel level 3
          NCPI                   Network Control Protocol Information,
                                 structure with additional protocol-
                                 dependent information.

          Note







                                     - 51 -


          COMMON-ISDN-API


          The meaning of the NCPI parameter depends on the protocol
          used. See SELECT_B3_PROTOCOL_REQ.


























































                                     - 52 -


                                                       COMMON-ISDN-API


          DISCONNECT_B3_RESP


          Description
          With this message the application confirms cleardown of a
          level 3 connection.

          Message
          Command/subcommand:    0x84 / 0x03
                                 WORD      NCCI

          Parameter
          NCCI                   Network Control Connection
                                 Identifier,transparent

          Note
          The NCCI is released with this message.











































                                     - 53 -


          COMMON-ISDN-API


          GET_B3_PARAMS_REQ - Request level 3 parameters


          Description
          This message can be used to request additional information
          on a level 3 connection. The level 3 connection is identi-
          fied via the NCCI.

          Message
          Command/subcommand:    0x85 / 0x00
                                 WORD      NCCI

          Parameter
          NCCI                   Network Control Connection
                                 Identifier, transparent













































                                     - 54 -


                                                       COMMON-ISDN-API


          GET_B3_PARAMS_CONF


          Description
          This message supplies the additional information on a level
          3 connection as requested with GET_B3_PARAMS_REQ. The level
          3 connection is identified via the NCCI. The parameter PLCI
          indicates the B-channel connection carrying the level 3 con-
          nection. Any errors are coded in the parameter info.

          Message
          Command/subcommand:    0x85 / 0x00
                                 WORD      NCCI
                                 WORD      PLCI
                                 WORD      Info

          Parameters
          NCCI                   Network Control Connection
                                 Identifier, transparent
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Info                   0:        Parameter available
                                 0x2003    Incorrect NCCI
                                 0x3205    NCCI not active




































                                     - 55 -


          COMMON-ISDN-API


          DATA_B3_REQ - Send level 3 data


          Description
          This message sends data on a level 3 connection. The level 3
          connection is identified by way of the NCCI. The length of
          the data area to be sent is stipulated via the parameter
          data length.

          The data to be sent is referenced via the parameter data.
          The data is thus not part of the message.

          The application issues a block number for this data area by
          way of the parameter number. On subsequent confirmation by a
          DATA_B3_CONF, this block number is also supplied.

          It is possible to set the additional information, such as
          more-data, delivery-confirmation, etc., via the parameter
          flags. The stipulated flags are not supported by all proto-
          cols.

          Message
          Command/subcommand:    0x86 / 0x00
                                 WORD      NCCI
                                 WORD      Data length
                                 DWORD     Data
                                 BYTE      Number
                                 WORD      Flags

          Parameters
          NCCI                   Network Control Connection
                                 Identifier, transparent
          Data length            Size of data area to be sent
          Data                   Pointer to the data to be sent
          Number                 Block number, transparent for the
                                 COMMON ISDN API, but referenced in
                                 DATA_B3_CONF
          Flags                  [0]       Qualifier bit
                                 [1]       More-data bit
                                 [2]       Delivery confirmation bit
                                 [3 to 15] Reserved

          Note
          The data area only counts as free if the COMMON ISDN API has
          sent a corresponding DATA_B3_CONF. The data transfer does
          not support assembly functions.














                                     - 56 -


                                                       COMMON-ISDN-API


          DATA_B3_CONF


          Description
          This message confirms the acceptance of a data package to be
          sent. The level 3 connection is identified by the parameter
          NCCI. The parameter number supplies the block number used by
          the application in the associated DATA_B3_REQ as a reference
          to the transferred data area.

          Message
          Command/subcommand:    0x86 / 0x01
                                 WORD      NCCI
                                 BYTE      Number
                                 WORD      Info

          Parameters
          NCCI                   Network Control Connection
                                 Identifier, transparent
          Number                 Block number, reference to number in
                                 corresponding DATA_B3_REQ
          Info                   0:        Data transmission initiated
                                 0x2003    Incorrect NCCI
                                 0x310A    Incorrectly coded flags
                                 0x3205    NCCI not active
                                 0x320D    Data length not supported


































                                     - 57 -


          COMMON-ISDN-API


          DATA_B3_IND - Indicate incoming level 3 data


          Description
          This message displays incoming data on a level 3 connection.
          The level 3 connection is identified via the NCCI. The
          length of the incoming data area  is stipulated via the pa-
          rameter data length.

          The incoming data to be sent is referenced via the parameter
          data. The data is thus not part of the message.

          The COMMON ISDN API issues a block number for this data area
          via the parameter number. On subsequent confirmation by a
          DATA_B3_RESP, this block number must also be supplied by the
          application.

          Additional information, such as more-data, delivery-
          confirmation, etc., is supplied by way of the parameter
          flags. The stipulated flags are not supported by all proto-
          cols.

          Message
          Command/subcommand:    0x86 / 0x02
                                 WORD      NCCI
                                 WORD      Data length
                                 DWORD     Data
                                 BYTE      Number
                                 WORD      Flags

          Parameters
          NCCI                   Network Control Connection
                                 Identifier, transparent
          Data                   Pointer to data received
          Data length            Size of data area received
          Number                 Block number, continuous, referenced
                                 in DATA_B3_RESP
          Flags                  [0]       Qualifier bit
                                 [1]       More-data bit
                                 [2]       Delivery confirmation bit
                                 [3 to 15] Reserved

          Note
          The data area only counts as free for the COMMON ISDN API if
          the application program has sent a corresponding DA-
          TA_B3_CONF.
          The data transfer does not support reassembly functions.













                                     - 58 -


                                                       COMMON-ISDN-API


          DATA_B3_RESP


          Description
          With this message the application confirms acceptance of an
          incoming data package. The level 3 connection is identified
          by the parameter NCCI. The parameter number stipulates the
          block number used by the COMMON ISDN API in the associated
          DATA_B3_IND as the reference to the transferred data area.

          Message
          Command/subcommand:    0x86 / 0x03
                                 WORD      NCCI
                                 BYTE      Number

          Parameters
          NCCI                   Network Control Connection
                                 Identifier, transparent
          Number                 Block number, reference to number in
                                 corresponding DATA_B3_IND








































                                     - 59 -


          COMMON-ISDN-API


          RESET_B3_REQ - Reset a connection / controller


          Description
          With this message the specified level 3 connection is reset.
          The level 3 connection is identified by way of an NCCI.

          Message
          Command/subcommand:    0x01 / 0x00
                                 WORD      NCCI

          Parameter
          NCCI                   Network Control Connection
                                 Identifier, transparent

          Note
          The reaction to a RESET_B3_REQ is dependent on the protocol
          employed. See also SELECT_B3_PROTOCOL_REQ.










































                                     - 60 -


                                                       COMMON-ISDN-API


          RESET_B3_CONF


          Description
          With this message the resetting of a level 3 connection is
          indicated.

          Message
          Command/subcommand:    0x01 / 0x01
                                 WORD      NCCI
                                 WORD      Info

          Parameters
          NCCI                   Network Control Connection
                                 Identifier, transparent
          Info                   0:        Reset executed
                                 0x2003    NCCI incorrect
                                 0x330A    Abort B-channel level 3
                                 0x330C    Reestablish B-channel level
                                           3

          Note
          If level 3 implementation does not provide for a reesta-
          blish, the corresponding connection is cleared down; this is
          reported in the parameter info.



































                                     - 61 -


          COMMON-ISDN-API


          RESET_B3_IND - Display connection reset


          Description
          With this message the resetting of a level 3 connection is
          signalled. The level 3 connection is identified by way of an
          NCCI.

          Message
          Command/subcommand:    0x01 / 0x02
                                 WORD      NCCI

          Parameter
          NCCI                   Network Control Connection
                                 Identifier, transparent













































                                     - 62 -


                                                       COMMON-ISDN-API


          RESET_B3_RESP


          Description
          With this message the application confirms the resetting of
          a level 3 connection.

          Message
          Command/subcommand:    0x01 / 0x03
                                 WORD      NCCI


          Parameter
          NCCI                   Network Control Connection
                                 Identifier, transparent


          Note
          This message has no function.









































                                     - 63 -


          COMMON-ISDN-API


          5.4 Telephone service


          HANDSET_IND - Report handset events


          Description
          The message HANDSET_IND transfers the events that occur on a
          connected telephone set. The telephone set here is taken to
          be an autonomous unit, i.e. the telephone service can be
          used at any time, even without the application program. In
          addition, it is also possible to link the set to an applica-
          tion program, which is then informed of all events occurring
          at the telephone set and can also setup and clear down con-
          nections independently.

          Message
          Command/subcommand:    0x87 / 0x02
                                 WORD      PLCI
                                 BYTE      Controller
                                 BYTE      Status

          Parameters
          Controller             Transparent
          PLCI                   Physical Link Connection Identifier,
                                 transparent
          Status                 IA5 characters
                                 '0'..'9','#','*','a','b','c','d':
                                             selected characters
                                 '+' :       Handset off-hook
                                 ' - '  :    Handset on-hook


          Note
          A telephone set is coupled to an application program under
          the following conditions:

          1 A LISTEN_REQ for the telephone service has been performed
            for the corresponding controller, or:

          2 The application has set up a connection for the telephone
            service with the message CONNECT_REQ. As long as the asso-
            ciated PLCI is valid, the events at the telephone set are
            reported.

          The "+" and "-" signs relate to status changes, they do not
          describe states.













                                     - 64 -


                                                       COMMON-ISDN-API


          HANDSET_RESP


          Description
          With this message the application confirms events at the te-
          lephone set.

          Message
          Command/subcommand:    0x87 / 0x03
                                 WORD      PLCI

          Parameter
          PLCI                   Physical Link Connection Identifier,
                                 transparent

          Note
          This message has no function.











































                                     - 65 -


          COMMON-ISDN-API


          5.5   Manufacturer-specific messages


          The manufacturer-specific messages are described below. Only
          the protocol is specified; information about the contents
          and the associated functions must be obtained from the manu-
          facturer.


          MANUFACTURER_REQ - manufacturer-specific request


          Message
          Command/subcommand:    0xFF / 0x00

          Parameter
          Manufacturer-specific











































                                     - 66 -


                                                       COMMON-ISDN-API


          MANUFACTURER_CONF


          Message
          Command/subcommand:    0xFF / 0x01

          Parameter
          Manufacturer-specific




















































                                     - 67 -


          COMMON-ISDN-API


          MANUFACTURER_IND - Manufacturer-specific indication


          Message
          Command/subcommand:    0xFF / 0x02

          Parameter
          Manufacturer-specific




















































                                     - 68 -


                                                       COMMON-ISDN-API


          MANUFACTURER_RESP


          Message
          Command/subcommand:    0xFF / 0x03

          Parameter
          Manufacturer-specific




















































                                     - 69 -


          COMMON-ISDN-API


          5.6   Other functions


          There are other local operations in addition to the message
          operations.
          Since these operations are operating-system-dependent, exam-
          ples of their implementation under MS-DOS are described in
          Annex A, Section 1, where the operations are dealt with in
          principle.


          5.6.1 Manufacturer identification


          Manufacturer identification is provided in plain text in AS-
          CII coding. The end of the identification is indicated by a
          0 byte. The maximum length of a manufacturer identification
          is 64 bytes. Examples of manufacturer identifications are
          given below:

          - AVM-GmbH - Version 1.0, revision 1.0
          - Stollmann GmbH
          - Systec

          It is proposed to add a version and revision number in plain
          text to the manufacturer identification. The format for this
          information can be ascertained from the manufacturer concer-
          ned.


          5.6.2 COMMON ISDN API version number


          The version number of the COMMON ISDN API is supplied in
          plain text in the format "Version 1.1, Profile A". This can
          optionally be followed by a manufactur-er's own revision
          number and a date. The end is indicated with a 0 byte.


          5.6.3 COMMON ISDN API serial number


          The (optional) serial number is provided in plain text in
          the form of a 7-digit number. If no serial number is to be
          used, the buffer must be returned empty. The end is indica-
          ted with a 0 byte.














                                     - 70 -


                                                       COMMON-ISDN-API


          6 Flowcharts

          For the specification of the flowcharts please ask for the
          written copy of the COMMON ISDN API specification.
























































                                     - 71 -


          COMMON-ISDN-API




                                                       COMMON-ISDN-API













                                         Annex A

                                  

                                 Implementation with different
                                     operating systems










                                       Version 1.1






























                                                       COMMON-ISDN-API


          1.    Implementation under MS-DOS

          As MS-DOS does not provide any multitasking facilities, the
          COMMON ISDN API is incorporated into the system as a back-
          ground driver (terminate and stay resident). The interface
          between the application and the COMMON ISDN API is implemen-
          ted by way of a software interrupt. The vector used for this
          must be configurable both in the COMMON ISDN API and in the
          application. The default value for the software interrupt is
          241 (0xF1). If another value is to be used, it can be speci-
          fied as a parameter when the COMMON ISDN API is called.

          The functions described above are defined by appropriate re-
          gister assignments at this software interrupt interface. The
          return values are supplied in register AX. The contents of
          all registers not used are retained.

          The COMMON ISDN API requires a maximum stack area of 512 by-
          tes for the execution of all the functions incorporated.
          This stack area must be made availabe to the application
          program.


          Implementation of the software interrupt

          The software interrupt for the COMMON ISDN API is defined
          according to the BIOS interrupt chaining structure.

          API   PROC        FAR            ;ISDN API interrupt service
                JMP         SHORT DOIT     ;Jump to start of routine
          O_API DD          ?              ;chained interrupt
                DW          424BH          ;interrupt chaining
                                            signature
                DB          80H            ;first in chain flag
                DB          'IA'           ;CAPI signature
          DOIT:

          The characters 'IA' can be requested by the application at
          offset 9 on the basis of this structure.


          Representation of a pointer

          The pointer stipulated in messages DATA_B3_REQ and DA-
          TA_B3_IND is implemented as a FAR pointer under MS DOS.














                                 Annex A - 1 -



          COMMON-ISDN-API


          Memory layout of basic data types

                      low-order word (adress n)          
                                                         
          <-- low order                                  
                                                         
          <------ Byte 0 -------><------ Byte 1 ------->
                                                        
          Ŀ                       
           7 6 5 4 3 2 1 0                       
                                 
                                                        
          Ŀ
           7 6 5 4 3 2 1 0151413121110 9 8
          
                                                        
          
           7 6 5 4 3 2 1 0151413121110 9 8
          


                     low-order word (adress n+1)         
                                                         
                                          higher order-->
                                                         
          <------ Byte 2 -------><------ Byte 3 ------->
                                                        
                                                        
                                                        
                                                        
                                                        
                                                        
                                                        
                                                        
                                                        
          Ŀ
          23222120191817163130292827262524
          

          Fig. 1: Memory layout

          Note: The figures in the boxes are bit numbers. The numbe-
                ring scheme starts at the low-order bit (0).


          1.1   Message operations under MS-DOS

          API_REGISTER - Registration of an application with the COM-
          MON ISDN API

          Description
          This is the function the application uses to report its pre-
          sence to the COMMON ISDN API. In doing so, the application






                                 Annex A - 2 -



                                                       COMMON-ISDN-API


          provides the COMMON ISDN API with a memory area. A FAR poin-
          ter to this memory area is transferred in registers ES:BX.
          The size of the memory area is calculated according to the
          following formula:

                ( 180 * CX ) + ( DX * SI * DI )

          The minimum number of messages that can be stored before
          data is lost is transferred to the CX register.

          In the DX register the application indicates the maximum
          number of level 3 connections opened simultaneously. An at-
          tempt to open more level 3 connections than stipulated here
          can be acknowledged with an error message by means of COMMON
          ISDN API.

          In the SI register the application sets the maximum number
          of received B3 data blocks that can be reported to the ap-
          plication simultaneously. The number of simultaneously avai-
          lable B3 data blocks has a decisive effect on the throughput
          of B3 data in the system. and should be between 2 and 7.
          There must be room for a B3 data block at least.

          In the DI register the application sets the maximum size of
          the B3 data to be transmitted and received. The setting of
          protocols that process larger packets, and the tranmis-
          sion/reception of larger packets can be acknowledged with an
          error message by the COMMON ISDN API.

          The application number is supplied in the AX register. In
          the event of an error, the AX register is returned with the
          value 0. The cause of the error is held in the BX register
          in this case.

          Parameters
          AH                     0x01
          ES:BX                  FAR pointer to a memory block provi-
                                 ded by the application. This memory
                                 area can be used by the COMMON ISDN
                                 API to manage the message queue of
                                 the application. In addition, the
                                 COMMON ISDN API can provide the re-
                                 ceived level 3 data in this memory
                                 area.

          CX                     No. of messages that can be stored
                                 before loss of data.
          DX                     Maximum no. of level 3 connections
          SI                     No. of B3 data blocks available si-
                                 multaneously
          DI                     Maximum size of a B3 data block








                                 Annex A - 3 -



          COMMON-ISDN-API


          Return value
          AX                     0x000     Registration error, cause
                                           of error in BX register
                                 <>0       Application no. (Appl-ID)
                                 0x1001    Registration error

          Note
          The maximum length of a message is defined as 180. If the
          application has opened a maximum of one level 3 connection
          simultaneously and the standard protocols are used, the fol-
          lowing register assignment is recommended:

                CX  =10, DX = 1, SI = 7, DI = 130

          The resulting memory requirement is 2710 bytes.












































                                 Annex A - 4 -



                                                       COMMON-ISDN-API


          API_RELEASE - Release an application from the COMMON ISDN
          API

          Description
          The application uses this function to log off from the COM-
          MON ISDN API. The memory area indicated in the API_REGISTER
          thus becomes free. The application is identified by way of
          the application number in the DX register. Any error that
          occur are returned in the AX register.

          Parameters
          AH                     0x02
          DX                     Application number

          Return value
          AX                     0x0000    No error
                                 0x1002    Incorrect application
                                           number









































                                 Annex A - 5 -



          COMMON-ISDN-API


          API_PUT_MESSAGE - Transfer message to the COMMON ISDN API

          Description
          With this function, the application transfers a message to
          the COMMON ISDN API. A FAR pointer is transferred to the
          message in the ES:BX registers. The application is identi-
          fied via the application number in the DX register. Any er-
          rors that occur are returned in the AX register.

          Parameters
          AH                     0x03
          DX                     Application number
          ES:BX                  FAR pointer to the message

          Return value
          AX                     0x00      No error
                                 0x01      Message too small or messa-
                                           ge number incorrectly coded
                                 0x1004    Incorrect command or sub-
                                           command
                                 0x1005    Message queue full

          Note
          After API_PUT_MESSAGE the application can again use the me-
          mory area for the message.


































                                 Annex A - 6 -



                                                       COMMON-ISDN-API


          API_GET_MESSAGE - Fetch message from COMMON ISDN API


          Description
          With this function, the application retrieves a message from
          the COMMON ISDN API. The application can only retrieve those
          messages intended for the stipulated application number. A
          FAR pointer is set to the message in the ES:BX registers. If
          there is no message for the application, the function imme-
          diately returns to the AX register with a corresponding er-
          ror value. The application is identified via the application
          number in the DX register. Any errors that occur are retur-
          ned to the AX register.


          Parameters
          AH                     0x04
          DX                     Application number


          Return values
          AX                     0x0000    No error
                                 0x1002    Incorrect application num-
                                           ber
                                 0x1006    Message queue was empty
                                 0x1007    At least one message to the
                                           application has been lost,
                                           since the message queue was
                                           full.
                                 ES:BX     FAR pointer to the message


          Note
          The message may be invalidated the next time API_GET_MESSAGE
          is called
























                                 Annex A - 7 -



          COMMON-ISDN-API


          1.2   Other functions under MS-DOS


          API_SET_SIGNAL - Set address of a signaling function


          Description
          The application can use this function to activate use of the
          signaling function. A FAR pointer to a signaling function is
          specified in the ES:BX registers. The signaling function can
          be deactivated by an API_SET_SIGNAL with register assignment
          ES:BX = 0000:0000.
          The application is identified via the application number in
          the DX register. Any errors that occurred are returned in
          the AX register.


          Parameters
          AH                     0x05
          DX                     Application number
          ES:BX                  FAR pointer to signaling function


          Return value
          AX                     0         No error
                                 0x1002    Invalid application number


          Note
          This signaling function settable with this function is cal-
          led by the COMMON ISDN API in the same manner as an inter-
          rupt. The flags are on the stack, the interrupts disabled.
          The signaling function must be terminated with IRET. None of
          the registers may be changed. At the time of calling, 32 by-
          tes are available on the stack.

          Care must be taken to ensure that this function can be cal-
          led at any time, e.g. even when an MS-DOS call is being pro-
          cessed.




















                                 Annex A - 8 -



                                                       COMMON-ISDN-API


          API_DEINSTALL - Remove the COMMON ISDN API


          Descirption
          The COMMON ISDN API is removed from memory and the memory
          area is released. The controllers are reset to their initial
          status. All ISDN connections, except for telephone connec-
          tions, on level 1 are released. If one or more application
          programs is registered with the COMMON ISDN API, the call
          API_DEINSTALL is terminated with an error value. In this
          case, setting the parameter Force to 0x001 can be used to
          force deinstallation.

          Parameters
          AH                     0x06
          BX                     Force
                                 0x0000    Normal deinstallation
                                 0x001     Forcible deinstallation


          Return value
          AX                     0         No error
                                 0x1008    Error during deinstallation


          Note
          If other application programs that call the COMMON ISDN API
          after deinstallation are installed, the results are not de-
          fined.






























                                 Annex A - 9 -



          COMMON-ISDN-API


          API_GET_MANUFACTURER - Fetch manufacturer identification


          Description
          With this function, the application determines the manufac-
          turer identification of the COMMON ISDN API. In registers
          ES:BX a FAR pointer is transferred to a data area of a least
          64 bytes. The manufacturer identification is present in this
          data area after
          the function has been executed. The end is indicated by a 0
          byte.

          Parameters
          AH                     0xF0
          ES:BX                  FAR pointer to buffer
                                 (at least 64 bytes in size)

          Return value
          ES:BX                  Manufacturer identification with AS-
                                 CII coding. The end of the identifi-
                                 cation is indicated with a 0 byte.

          API_GET_VERSION - Fetch version number of the COMMON ISDN
          API


          Description
          With this function the application determines the version of
          the COMMON ISDN API. In registers ES:BX a FAR pointer is
          transferred to a data area of a least 64 bytes. The version
          is present in this data area in the form "Version 1.1, Pro-
          file A ..." after the function has been executed. The end is
          indicated by a 0 byte.

          Parameters
          AH                     0xF1
          ES:BX                  FAR pointer to buffer
                                 (at least 64 bytes in size)

          Return value
          ES:BX                  The version number of the COMMON ISDN
                                 API is returned in plain text in the
                                 form Version 1.1, Profile A. It may
                                 optionally be followed by a revision
                                 number and date. The end of the ver-
                                 sion number is indicated with a 0
                                 byte.












                                 Annex A - 10 -



                                                       COMMON-ISDN-API


          API_GET_SERIAL_NUMBER - Fetch (optional) serial number


          Description
          With this function, the application determines the (optio-
          nal) serial number of the COMMON ISDN API. In registers
          ES:BX a FAR pointer is transferred to a data area of a least
          64 bytes. The serial number is present in this data area in
          the form of a seven-digit number after the function has been
          executed. The end is indicated by a 0 byte. If no serial
          number is supplied, the end of the serial number is marked
          in the first digit position.

          Parameters
          AH                     0xF2
          ES:BX                  FAR pointer to buffer
                                 (at least 64 bytes in size)

          Return value
          ES:BX                  The (optional) serial number is re-
                                 turned in plain text in the form of a
                                 7-digit number. If no serial number
                                 is to be used, a 0 byte must be writ-
                                 ten at the first position in the buf-
                                 fer. The end of the serial number is
                                 indicated with a 0 byte.

































                                 Annex A - 11 -



          COMMON-ISDN-API


          API_MANUFACTURER - Manufacturer-specific function


          Description
          This function is manufacturer-specific.

          Parameter
          AH                     0xFF

          Use of the other registers is manufacturer-specific.

          Return value
          Manufacturer-specific.














































                                 Annex A - 12 -



                                                       COMMON-ISDN-API




                                                       COMMON-ISDN-API













                                         Annex B

                                  

                                        Profile










                                       Version 1.1































                                                       COMMON-ISDN-API


          1.     Profile of the COMMON ISDN API


          The different signaling protocols used internationally in
          ISDN systems differ particularly with respect to their re-
          presentation of data. Accordingly, within the COMMON ISDN
          API the data representation is defined with profiles, in
          which the necessary decis

          This ensures that the COMMON ISDN API can be adapted to fu-
          ture expansions and modifications of the data representa-
          tion. At present, profile A provides referencing to 1TR6.
















































                                 Annex B - 1 -


          COMMON-ISDN-API


          1.1  Profile A - Representation in accordance with 1TR6


          Data element                    Reference
          -------------------------------------------------

          Additional byte of
          service ind.                     1 TR 3, Part 5
                                           Chapter 3.2.3.4.5.3 Octet 4

          Caller address                   1 TR 3, Part 5
                                           Chapter 3.2.3.4.4.10 Octet
                                           3ff

          Cause                            1 TR 3, Part 5
                                           Chapter 3.2.3.4.4.4 Octet 3

          Channel identification           1 TR 3, Part 5
                                           Chapter 3.2.3.4.4.7 Octet 3

          Charging information             1 TR 3, Part 5
                                           Chapter 3.2.3.4.5.4 Octet
                                           3ff.

          Connected address                1 TR 3, Part 5
                                           Chapter 3.2.3.4.4.5 Octet
                                           3ff.

          Date                             1 TR 3, Part 5
                                           Chapter 3.2.3.4.5.5 Octet
                                           3ff.

          Destination address              1 TR, Part 5
                                           Chapter 3.2.3.4.4.11

          Display                          1 TR 3, Part 5
                                           Chapter 3.2.3.4.4.9

          EAZ                              IA5 character, '0' to '9'
                                           1 TR 3, Part 5
                                           Chapter 3.2.3.4.3,
                                           Table 3-60b


















                                 Annex B - 2 -


                                                       COMMON-ISDN-API


          Data element                    Reference
          ----------------------------------------------------

          Info number
            bits 0 to 7:                   Number of W element
                                           1 TR 3, Part 5
                                           Chapter 3.2.3.4.4ff

            bits 8 to 10:                  Code set
                                           1 TR 3, Part 5
                                           Chapter 3.2.3.4. ff


          Service indicator                1 TR 3, Part 5
                                           Chapter 3.2.3.4.5.3 Octet 3

          Status of called party           1 TR 3, Part 5
                                           Chapter 3.2.3.4.4.3 Octet 3

          Type/plan                        1 TR 3, Part 5
                                           Chapter 3.2.3.4.4.11 Octet
                                           3

          User-user information            1 TR 3, Part 5
                                           Chapter 3.2.3.4.4.15 Octet
                                           3ff


































                                 Annex B - 3 -


          COMMON-ISDN-API


          This documentation has been prepared with great care. Never-
          theless, it may contain certain errors and inconsistencies.
          The right to incorporate modifications in the interests of
          technological progress is reserved.

          Protected trademarks are not identified as such in this do-
          cumentation. The fact that such identification is not provi-
          ded does not signify that the name may be used freely.


          This document may be copied and distributed, provided the
          publication details are stated.





          Publisher: ISDN-PC working group of the german
                     Deutsche Bundespost TELEKOM and the
                     companies AVM, Stollmann and Systec




          Editor:    AVM Berlin GmbH
                     Voltastrae 5
                     D-1000 Berlin 65
                     Tel: 030/46 45 051
                     Fax: 030/46 45 056






























                                 Annex B - 4 -

.

