When an IP phone (A) dials an analog phone (B), the call is made through the AS5350 gateway to the phone and rings. When there is no answer, the private branch exchange (PBX) transfers the call to Cisco Unity at 8100 but the caller hears the opening greeting and not the subscriber's greeting. When a call is made from the same phone (A) to a different analog phone (C), the call is made through the Media Gateway Control Protocol (MGCP) gateway 2821 and then connects to the PBX. When the phone is not answered, they are successfully transferred to the user's voicemail box registered to (C) and can successfully leave a message.
Q.SIG facility messages are sent to the Cisco CallManager via the AS5350 as an H.323 gateway. The AS5350 does not support the facility field.
These things must be considered for the configuration of Q.SIG supplementary features for the Cisco IOS voice gateways:
You need to run Cisco IOS Software Release 12.3(11)T or later.
MGCP must be configured on the voice gateway.
ISDN PRI backhaul must be configured on the MGCP gateway.
Q.SIG signaling is required to support supplementary services over the T1 and E1 time-division multiplexing (TDM) trunks that support the PRI backhaul mechanism.
Cisco Catalyst 6500 series and Cisco 7600 series Communication Media Module (CMM) requires either the WS-SVC-CMM-6T1 or WS-SVC-CMM-6E1 port adapter.