Fault phenomenon: the customer said the users under SIP protocol’s IAD configured call forward business, occasionally will appear call forward not successful, prompt "dialed is busy"
1, please customers use the user under user box test, found in call forward busy can be successful.
2, if user A configuration call forward busy, please customers test, when A in calling, dial A again the call forward busy success, the customer says it can be successful.
3, when A pick machine and not dial, other users call A, encounter call forward busy whether can success, the customer said that the forward failure, prompt "dialed is busy".
4, check when the IAD user off-hook unfinished dialing, whether the user state in Softco is consistent with the state on IAD. The results show that the Softco state is idle, the IAD is busy.
1, The users state recorded in Softco system is not consistent with the state of the IAD.
This situation can't avoid, due to the call forward busy business is completed by Softco alone, not happen signaling interaction with IAD. And the SIP protocol’s character decides that in the dialing process, IAD is not launch INVITE event to Softco, Softco don't know the users under IAD are in a busy state. So when access the telephone to IAD, find the starting phone has already picked up after reached IAD, so can only can give dialing prompting busy tone, and cannot realize forwarding.