How CMS callbridge selects TURN server?

[xujf]

    In my system design and deployment,  I have one CMS call-bridge in central IDC  and 4 edge/TURN servers in 4 SPs network. lease lines are used between call-bridge and TURN server.

    Intelligent DNS is used , CMA client selects TURN based on DNS,CMA always select TURN that locate in its own SP's network.but call bridge select another TURN server.

  I hope call bridge could select the TURN server that is same as CMA client's TURN server. 

  CMS support multiple TURN server,  each TURN server configure two IP :  public IP, Private IP.  I hope  when CMA select Public IP, then Call bridge select private IP that is same  TURN as of  CMA selection. 

  May I reach this target? 

[xujf]

I just want to know how CMS select TURN server when I configure many TURN servers?

[Sushant Sharma]

Hi ,

anyone know about this , how callbridge select turn server 

[robertb]

Would be interested to see a response as im looking for the same answer.

I haven't had the greatest experience with CMS and the use of TURN on expressway with large volumes. Poor quality, disconnects and some unable to join because of the current 70 session limit. One can allocate a TURN server to a bridge but what if you have 3? how does CMS select one, based on the same proccessing as load balancing calls on the CB?

The most I've seen on selection methods is based on RTT seen in API:

https://<Callbridge_IP>:445/api/v1/turnservers/<turnServer id>/status

The output displays information which includes the Round-trip time (RTT) in milliseconds (Ms) associated to the TURN server. This information is important to the CB selection of the best TURN server to use.

Endless problems that Cisco TAC can't figure out either.