RTP header compression using fast switching causes poor voice quality over Frame Relay

[TCC_2]

Core Issue

The cause of this problem is a bug associated with fast switched Real-Time Protocol (RTP) header compression.

The voice is still intelligible and may be described as an underwater voice.

Resolution

The issue is resolved in Cisco bug ID CSCdy57722 by a Cisco IOS  Software upgrade.

For a workaround, perform these steps:

1. Disable the RTP header compression link.
2. Disable fast switching on the Frame Relay connection by issuing the no ip route-cache command under the interfaces.Note: This may cause the router's CPU to increase, as it now uses the process-switched path.

To resolve the problem, use a version of Cisco IOS Software that includes the fix for Cisco bug ID CSCdy57722.

Voice Gateways

1700 Series Access Router