We have been having some issues with voice recording, only one side of the conversation is being recorded, Cisco side.
Examples of two different calls:
Cisco phone (local Cluster CUCM 11.5) to an external number (PSTN) over a Voice Gateway only hear the cisco side
Cisco phone (local Cluster 11.5) to another PBX over SIP trunk, the recording system generates two files, one for the Cisco Phone and the other for the PBX phone (PBX is also connected to the recorder system), in case of the Cisco phone it can be hear one side, in case of the PBX phone both side as should be. This makes me think that the problem doesn't reside in the recorder system but in our Cluster. Maybe Codec Issues?
i had this problem as well. but it turns out i was listening to recordings with a mono headset so was only getting half the recording. unplugged my headset and played recording through laptop speakers and all OK, wasted 2 days with vendor trying to work out what was wrong.