[cisco-voip] Inbound Calls [Dead Silent]

[Tamer Mohamed Bayomy]

Dear All,

I'm using Cisco voice gateways and I'm having a problem where some
inbound calls are completed successfully to their destinations but when
the other end answer the call both ends hear a dead silent.. Is there
anyone experience the same problem..?!! How did you manage to overcome
this problem?!! Any help?!! 

Note,
Not all the calls are silent but only 10% silent calls.

Regards, 
Tamer