Troubleshooting example of MGCP protocol-NAT environment mapping is inactive, resulting in mute after a call period

Reason: in the NAT environment, the inactivation of the mapping relationship causes the media stream on the public network to be unable to pass through the NAT device, resulting in call muting.

Malfunction: mute occurs after talking for a period of time

Device packet prompt message:

Cause analysis: through the analysis of the information of the silent packet, it is found that after a period of time, the device can not receive the media stream information of the platform. Combined with the device operating environment of NAT, it is speculated that due to the inactivation of NAT recording, the media stream of the public network cannot pass through the NAT device, resulting in mute.

Treatment measures:

1. Enable the rtcp function of the device to send rtcp messages periodically to keep the NAT mapping record alive.