3g call failure

Hi All,

3G network we have taken trace using packet tracer from this we have observed the contact URI send by client is different when it received on server side.

Client send contact URI as Via: SIP/2.0/UDP;branch=z9hG4bK-1505690283;rport
but on server side it Via: SIP/2.0/UDP;branch=z9hG4bK-1505690283;rport

Here the ports number is vary becuase of that the call is failed in 3g network.
Please help me in this , what is the reason for this issue.

Note: we are using TURN server


Hi All,

On further analysis i have found the MTU value is 1514 on UDP. I have a doubt that the same value send in wifi network but call working, the same length not working in 3G network.

How it is possible? if the packet length crossed 1500 MTU it will get problem in wifi also. But we having the problem in 3g network.

Please help me in advance, i’m stuck up with this problem for more than month.



Via is not the same as Contact.

You will have to ask the router manufacturer.