Browse Prior Art Database

Method of Controlling and Managing ISDN Layer 3 Connections

IP.com Disclosure Number: IPCOM000107301D
Original Publication Date: 1992-Feb-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 8 page(s) / 239K

Publishing Venue

IBM

Related People

Ellesson, EJ: AUTHOR [+7]

Abstract

Integrated Services Digital Networks (ISDN) provide attaching clients the capability of establishing connections or calls through the network to a remote client. In addition, ISDN provides services that may be utilized by clients to manage active calls (e.g., ISDN Supplementary Service - Call Waiting).

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 28% of the total text.

Method of Controlling and Managing ISDN Layer 3 Connections

       Integrated Services Digital Networks (ISDN) provide
attaching clients the capability of establishing connections or calls
through the network to a remote client.  In addition, ISDN provides
services that may be utilized by clients to manage active calls
(e.g., ISDN Supplementary Service - Call Waiting).

      This invention enables an application to address, set up and
take down, and manage ISDN Layer 3 (Layer 3 connections are defined
in this article by International Telegraph and Telephone Consultative
Committee (CCITT) International Standard Q.931 and Q.932) connections
with minimal switch or network-specific impact to the host
application/ISDN Communication Subsystem (CSS) interface.

      Layer 3 connection control and management include:
      1.   Establishing addressing for a particular ISDN call.
      2.   Initiating or accepting ISDN calls.
      3.   Clearing particular (and removing addressing) for a
particular ISDN call.
      4.   Causing specific functions (e.g., ISDN Supplementary
Services like Call Wait, Call Forwarding, etc.) to be performed on
specific ISDN calls.

      Control and Management of Layer 3 connections by a host
application is accomplished by exchanging implementation-independent
messages or primitives between the host application and a
communications subsystem.  The primitives instruct the communications
subsystem to perform specific functions such as call set up, call
clear, call waiting, etc. (see Fig. 1).

      Note:  The transport mechanism used to exchange the primitives
between the Host application and the communications subsystem is not
part of this invention and is implementation specific.

      The primitives defined in this invention are:
      Primitive           Description
      CALL SETUP          This primitive instructs the CSS or
                Host
                          Application to set up and establish the
addressing for a Layer 3 ISDN connection to be initiated or received.
                          This primitive has four forms:
                          1.   Request - Issued by the Host
Application to the CSS.
                          2.   Confirm - Issued by the CSS to the
Host (contains the completion status of the requested CALL SETUP).
                          3.   Indication - Issued by the CSS to the
Host indicating that a SETUP has been received.
                          4.   Response - Issued by the Host
application to the CSS contains information regarding acceptance or
rejection of the call.
      CALL CLEAR          This primitive instructs the CSS to clear
or take down the switched connection and remove addressing for that
Laye...