《《ISDN Cause Codes》.pdfVIP

ISDN Cause Codes Including current information from: North American ISDN Users Forum ITU Standards activity ANSI ISDN Cause Codes Fourth edition, published February, 22, 2003 by: Unlimited right to copy this document is granted to anyone as long as the document is copied in its entirety; including all cover pages, and this title page. Copyright © 1995, 1996, 1997 2003 by AHK Associates, Inc. Disclaimer This information has been compiled from many sources by AHK Associates . Care has been taken to ensure the accuracy of this information, but no guarantee or warranty is implied or offered as to accuracy or usefulness. User assumes any and all risk or liability in using this information. Introduction Several things can go wrong during the ISDN call setup. When they do the network will signal the nature of the fault via a code. When de -coded, the reason it occurred can be determined. Here are several examples of faults that can be reported. A setup request for a specific B-Channel when that channel is in use will cause the network to send a set release complete message with cause code # 44 “Requested circuit/channel unavailable”. A setup request for a B channel when all B-Channels are in use will receive a release complete message from the network with cause code # 34 “No circuit/channel available”. The network might ignore a setup message with elements out of sequence. Procedures for this event are undecided. If the element is a vital one (e.g., called party number) the network could respond with setup acknowledge in place of call proceeding, and wait for additional information. A setup message with duplicated elements