12-04-2014, 12:55 AM
Both phones are inside a LAN.
The SIP-PBX is in an external WAN.
Both phones always work perfect with outgoing calls.
The problem occurs with incoming calls:
Just after booted, both phones are reachable for incoming calls, sometimes.
But most of the time the phones cannot be connected from the external PBX.
Interresting:
Two different softphones from other venders in the same LAN work perfectly well for incoming calls with that external PBX.
The PBX vendor (Starface) analyzed the PBX logs and says:
The softphones might have a relative short keep alive signal period which keeps the way through the NAT router.
But the Yealink phones seem to have a very long keep alive every 60 minutes or so and it might be, that the NAT-router does not hold it's NAT-tables for such a long period and therefore starts to deny before the next keep alive signal.
Question:
Is it possible to shorten the keep alive signal period at the T46G and T48G?
Or do you have another suggestion?
The SIP-PBX is in an external WAN.
Both phones always work perfect with outgoing calls.
The problem occurs with incoming calls:
Just after booted, both phones are reachable for incoming calls, sometimes.
But most of the time the phones cannot be connected from the external PBX.
Interresting:
Two different softphones from other venders in the same LAN work perfectly well for incoming calls with that external PBX.
The PBX vendor (Starface) analyzed the PBX logs and says:
The softphones might have a relative short keep alive signal period which keeps the way through the NAT router.
But the Yealink phones seem to have a very long keep alive every 60 minutes or so and it might be, that the NAT-router does not hold it's NAT-tables for such a long period and therefore starts to deny before the next keep alive signal.
Question:
Is it possible to shorten the keep alive signal period at the T46G and T48G?
Or do you have another suggestion?