With Cisco CallManager, you might experience a one-way voice issue after you transfer a call or place a call on hold, if the H.323 endpoint that is configured on the CallManager is a FastEthernet subinterface of the gateway. This occurs especially when music on hold (MOH) is enabled.
There are no specific requirements for this document.
This document is not restricted to specific software or hardware versions.
Refer to Cisco Technical Tips Conventions for more information on document conventions.
The IP phone sends Real-Time Transport Protocol (RTP) packets to the wrong IP address after it resumes a transferred or on-hold call.
Complete these steps in order to solve the problem:
On the gateway, configure a loopback interface and the h323-gateway voip bind srcaddr ip_address command, as described in H.323 Support for Virtual Interfaces. Ensure that you use this loopback IP address when you configure the Cisco IOS H.323 gateway.
Globally configure voice rtp send-recv on the gateway.
This command is documented in Cisco IOS Voice, Video, and Fax Commands: Si through Z.
Verify that you have selected correct MOH codecs in the service parameters for Cisco IP Voice Media Streaming Applications.
See the Related Information