Browse Prior Art Database

Allow Unsupported Elements to be Sent in ISDN Q931 Messages

IP.com Disclosure Number: IPCOM000112226D
Original Publication Date: 1994-Apr-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Ritchie, AJ: AUTHOR [+2]

Abstract

Disclosed is a method by which ISDN CCITT Q931 Information Elements (IEs) that are not supported by a network are transported by that network.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Allow Unsupported Elements to be Sent in ISDN Q931 Messages

      Disclosed is a method by which ISDN CCITT Q931 Information
Elements (IEs) that are not supported by a network are transported by
that network.

      Most networks transport transparently some IEs from end-user to
end-user.   By encoding a CCITT IE not supported by the network into
such an IE and decoding it back into the CCITT IE at the receiving
end allows unsupported IEs to be transmitted transparently by the
network.  This means that applications can be ported from one network
to another without change.

      For example, in the German 1TR6 network the Lower Layer
Compatibility IE, LLC, is not supported.    However, there is an IE
supported by the network, Service Indicator, which it transports
transparently.   So by encoding an LLC IE into a Service Indicator IE
and transmitting it to the network, and at the receiving side
decoding the received Service Indicator into an LLC IE, the LLC IE
will seem to have been transmitted transparently by the network.

      Fig. 1 illustrates how an IE which is supported by a network is
transported, the contents of the IEs are represented by the
hexadecimal numbers under them.

Sending End                   Network             Receiving End

------------                  --------            --------------

Called Party Number IE                         Called Party Number IE

7003803132             ------------------------>  7003803132

 Fig 1: Transportation of CCITT IE which is supported by a Network.

The technique described in this disclosure is illustrated in Fig 2.

Sending End                   Network            Receiving End

------------                  --------       ...