CMS Edge as a Turn server and the issue of reachable = false with the callbridge, how to solve it

When you deploy Cisco Meeting Server as CMS Edge instead of Cisco Expressway, it will act as the turn server to connect external WebRTC users to the CallBridge providing the NAT Traversal solution.

Sometime you can meet the following issue where the configuration of turn server is correct and the callbridge is configured under the API configuration with the correct settings of turn server as shown below.

On CMS Edge:

turn short_term_credentials_mode enable

turn short_term_credentials cisco cms

turn public-ip

turn listen a

turn tls 3478

turn certs edge.key edge.crt Bundle-CA.crt

turn enable

On CallBridge:

The configuration seems correct and it’s straight forward, but the connection status shown that that the Call Bridge cannot connect to the turn server as shown below with the message Reachable = False.

When you do packet capture using the PCAP MMP command on either the Core CMS (CallBridge) or on the CMS Edge (Turn server), you will find that the CallBridge is sending a stun message Allocation Request. But the Turn server is not responding back to the CallBridge as shown below.

From the WerRTC ‘s perspective, the cisco meeting APP cannot establish media with the callbridge through the turn server, in other words, the Cisco Meeting APP cannot connect to a meeting or a conference.

To solve this issue, you need to configure the time zone on the Turn Server using the timezone MMP command.

Once the timezone is configured the status will be Reachable = True.

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