ISDN Events |
Under normal situations, the source of this cause is not the network.
Cause No. 17: user busy. The called user has indicated the inability to accept another call.
It is noted that the user equipment is compatible with call.
Cause No. 18: no user responding. The user does not respond to a call establishment message with either an alerting or connect indication within the prescribed period of time allocated (defined in Recommendation Q.931 by the expiration of either timer T303 or T310).
Cause No. 19: no answer from user (user alerted). The user has provided an alerting indication but has not provided a connect indication within a prescribed period of time.
This cause is not necessarily generated by Q.931 procedures but may be generated by internal network timers.
Cause No. 21: call rejected. The equipment sending this cause does not wish to accept this call, although it could have accepted the call because the equipment is neither busy nor incompatible.
Cause No. 22: number changed. The called party number indicated by the calling user is no longer assigned. The new called party number may optionally be included in the diagnostic field. If a network does not support this capability, Cause No. 1 shall be used.
Cause No. 26:
Cause No. 27: destination out of order. The destination indicated by the user cannot be reached because the interface to the destination is not functioning correctly. The term “not functioning correctly” indicates that a signaling message was unable to be delivered to the remote user, for example, a physical layer or data link layer failure exists at the remote user’s site, or the user equipment is
Cause No. 28: invalid number format (address incomplete). The called user cannot be reached because the called party number is not a valid format or is not complete.
