No voice when transferring call

There is no voice when transfer an inbound call to another agent on same server. Scenario is

inbound call (person P) —> receive by caller A —(transfer to)----> Caller B ( issue is caller B and person P can not hear voice)

We have two ip One is public and other is private.

Please suggest.

Check the settings for localnet as well as externip/externhost in Your sip.conf.
For further assistance here in the forum we’ll need at least a sip debug of the involved parties in Your scenario.