Common Isdn Cause Codes; Table 6 Common Isdn Cause Codes - Nortel BayStack 100-S Install Manual

98 Appendix C Troubleshooting and error messages

Common ISDN cause codes

If there is a problem with your ISDN line, the unit log is displayed and the
appropriate ISDN disconnection cause code is recorded at the end of the log.
Table 6

Table 6 Common ISDN cause codes

Cause code
16
17
18
19
21
31
34
127
145
146
209226-B
describes common ISDN cause codes.
Meaning
Normal call clearing [Q.850] – Indicates that the call is being cleared
because one of the users involved in the call has requested that the call
be cleared. Under normal situations, the source of this cause is not the
network.
User busy [Q.850] – Indicates that the called party is unable to accept
another call because the user busy condition has been encountered. This
cause value may be generated by the called user or by the network. In
the case of user determined user busy it is noted that the user equipment
is compatible with the call.
No user responding [Q.850] – Indicates that a called party has not
responded to a call establishment message with either an alerting or
connect indication within the prescribed period of time.
No answer from user (user alerted) [Q.850] – Indicates that the called
party has been alerted but does not respond with a connect indication
within the prescribed period of time. Note: This cause is not necessarily
generated by Q.931 procedures but may be generated by internal
network timers.
Call rejected [Q.850] – Indicates that the equipment sending this cause
can accept the call (it is neither busy nor incompatible), but will not. This
cause may also be generated by the network, indicating that the call was
cleared due to a supplementary service constraint. The diagnostic field
may contain additional information about the supplementary service and
reason for rejection.
Normal, unspecified [Q.850] – Used to report a normal event only when
no other cause in the normal class applies.
No circuit/channel available [Q.850] – Indicates that there is no
appropriate circuit/channel presently available to handle the call.
Interworking, unspecified [Q.850] – Indicates that an interworking call
(usually a call to SW56 service) has ended.
Data link failure
TEI or SID (USA) negotiation failure