Multiple RE behind same NAT

[lebenton]

Can multiple Remote Extensions (RE) be supported when setup behind the same NAT router remotely??



I tried setting up more than 1 REs behind the same NAT router, but find
that although the register and make outbound calls successfully,
calling the these REs from the extensions under the host Quadro often
fails. smileys/smiley5.gif



I'm guessing it's because these REs are using the same SIP signaling
port (5060) so the NAT router is having difficulties routing inbound
SIP invites to the correct RE...?

[davrays]

Yes, thats correct. When RE is making a call from behind the NAT, the NAT router creates a dynamic mapping for that RE. While this mapping exists, you can call to that RE from the host Quadro. When thismapping is removed from NAT router after timeout, calls from host Quadro will fail.BTW this mapping can be opened by both SIP INVITE, and registration, so it may seem to you that ability to call to that RE from host Quadro is "random".


Of course, there can be other reasons for REs not working behind the NAT - you have to make sure that STUN is configured correctly on RE, or, if you don't have STUN on that RE, or don't want to use it, you need to use "Symmetric RTP" feature of Quadro.