Audio portion of call being dropped on On prem Cisco PBX systems
Calls from the ARD connect with the Cisco endpoint but then lose the audio portion of the call.
This behavior can be the result of the Cisco PBX dropping the audio packets because they exceed the default maximum packet size for SIP calls.
This was common on older versions of Cisco CUCM but has been addressed in later versions of the Cisco CUCM software.
This Cisco Article explains the behavior, cause, and solution.
The customer must make the suggested changes to configure Cisco to handle the larger packet sizes.