I have a CUCM 7.1.3 integrated with a Alcatel OXO PBX and when a try to place a call from cisco IP-Phones registered on CUCM to phones on PBX, I have no ringback,but when a place a call from cisco IP-Phones registered on CUCM to PSTN using PBX as it has a PRI line to the local PSTN, I dont have that issue.
The voice gateway connects to PBX using a PRI(E1) running MGCP and QSIG.
interface Serial 3/1:15
no ip address
encapsulation hdlc
isdn switch-type primary-qsig
isdn timer T310 120000
isdn protocol-emulate network
isdn incoming-voice voice
isdn bind-l3 ccm-manager
no cdp enable
