The topology is as follows:
IP phone--->CCM--->H323---->2851--->T1 Controller--->MX/Alliance Turret System.
The MX/Alliance T1 is configured for FXS-Loopstart and SF/AMI. When the T1 controller on the 2851(H323 gateway) is configured for FXO-Loopstart and SF/AMI, calls from the IP Phone to the Turret work fine but the 2851 fails to detect the incoming siezure from the MX/Alliance system.
This results in the continuous ringing of the IP phone although the other party(MX/Alliance Turret System) has picked up the phone. This happens when making an outbound call from the IP phone to the Turret.
This happens due to the non-standard signallnig used by the MX/Alliance system.
To overcome this problem, insert a RAD Vmux 2100 Circuit Emulation/Transport Device between the Cisco IOS gateway T1 Controller and the MX/Alliance Turret system.
Since the Vmux 2100 Circuit Emulation/Transport device converts TDM to IP and back to TDM, the Cisco IOS gateway can be configured for E&M Immediate-Start, ESF/B8Zs while the MX/Alliance Turret system remains configured as T1 FXS-Loopstart and SF/AMI.
For related information, refer to: Private Line Automatic Ringdown for Trading Turrets