Switching from UDP-TCP-UDP then TCP

[Chidado]

On occasion, we have very few clients that we have to (Cisco-Yealink) switch protocols from UDP-TCP-UDP and so on. We know it s the firewall, but where? What to isolate and change? Always Rogers Modems as well. Has anyone firmly shut that nonsense down?

 

[DigitalDaz]

Sorry, no idea what you are saying here.

 

[Chidado]

Yealink and Cisco allow the phones to use either TCP or UDP to communicate. We have to constantly switch between UDP/TCP to allow the phones to register. One day it could be TCP then fail, then switch to UDP and we may be good for a few days. Then back to TCP.

 

[DigitalDaz]

Do they have a sip alg?

You would really need to analyse the traffic from the phone at the phone end and at the server to see what is not getting through correctly.

 

[Chidado]

checking SIP ALG....