Troubleshooting
ISDN cause codes
MultiVoice Gateway for the MAX— User’s Guide
Preliminary November 23, 1998
A-7
ISDN cause codes
ISDN cause codes are numerical diagnostic codes sent from an ISDN switch to a DTE. These
codes provide an indication of why a call failed to be established or why a call was terminated.
The cause codes are part of the ISDN D-channel signaling communications supported by the
Signaling System 7 supervisory network (WAN). When you dial a call from the MultiVoice
Gateway over a line with ISDN signaling, the MultiVoice Gateway reports the cause codes in
the Message Log status menu. When the MultiVoice Gateway clears the call, a cause code is
reported even when inband signaling is in use. If the PRI or BRI switch type is 1TR6
(Germany), see Table A-7.
Table A-6 lists the numeric cause codes and provides a description of each.
Table A-6. ISDN cause codes
Code
Cause
0
Valid cause code not yet received
1
Unallocated (unassigned) number
2
No route to specified transit network (WAN)
3
No route to destination
4
Send special information tone
5 Misdialed
trunk
prefix
6
Channel unacceptable
7
Call awarded and being delivered in an established channel
8
Prefix 0 dialed but not allowed
9
Prefix 1 dialed but not allowed
10
Prefix 1 dialed but not required
11
More digits received than allowed, but the call is proceeding
16
Normal clearing
17
User busy
18
No user responding
19
No answer from user (user alerted)
21
Call rejected
22
Number changed
23
Reverse charging rejected
