After Cisco IPICS implementation, this work around 15 days. After that, our customer experienced an issue with the audio. I'll try to explain the behavior.
When a user uses a Cisco IP Phone Service (on IP Phone 6921 & 7945) to communicate with Radios, the communication is success and we can see the led of E&M card that indicate communication, If we activate two or three IP Phones with the service and try again, all IP Phones and All radios can hear the message. The issue is when a user PTT on Radios, the message only hear on Radios but not on Cisco IP Phones, when we do this test the E&M card led not indicate communication only appear off.
I tried running a debug "debug vpm signal" on Cisco IPICS GW and when the communications flow is Cisco IP Phone Service -> Radio, I received a lot of messages from the debug, but when the communications flows is from Radio -> Cisco IP Phone Service I didnt receive anything.
I tried replacing the E&M Cards and the behavior is the same, I tried too replacing cables (4 cables) between IPICS gw and Radio and still the same behavior.
Do you have any idea about what happening? or is there missing configuration?
Cisco IPICS 4.5(1)
debug vpm signal (Cisco IP Phone -> Radios)
debug vpm signal (Radios -> Cisco IP Phone)
debug voip hpi checker (Radios -> Cisco IP Phone)