We have integrated our CUCM 8.0 with Vocalcom callcenter, when an agent initiates a call from the Vocalcom client software (which is intalled on the agent PC) to a customer outside in PSTN, the called party can't hear the voice of the agent, but the agent can hear the called party, this behavior is intermittent.
When we ran wireshark on the Vocalcom server itself, we could hear both party voice for the same particular call, however when it reaches the PSTN user, the audio from the agent is not heard. call flow as below. Tried to enable MTP, but same behavior. Any assistance appreciated.
Vocalcom client > Vocalcom server > SIP > CUCM > H.323 > Cisco VG > E1 PRI > PSTN
I have configured transcoder and Conference bridge on the router and registered in the CUCM, associated the same on the SIP trunk. Attached VG config.