Connections to multiple VOIP provider

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mruane

420 posts

Ultimate Geek

#12845 9-Apr-2007 12:25

Hi

I have mulitple VOIP providers and three VOIP devices (a WAG54GP2 with two VOIP ports and a Handytone 486). When establishing connections to each provider must I use a distinct TCP port i.e. 5060, 5061 etc for each connection, or can all of the connections be on port 5060 relying on perhaps a MAC address to sort out the traffic.

Cheers Mike

richms

28168 posts

Uber Geek

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Lifetime subscriber

#66684 10-Apr-2007 02:13

I have run multiple ata's here with several providers externally, soft phones and also asterisk running on a machine here, only asterisk needed ports fowarded to it, everything else used stun and sorted itself out. One of the atas (my one, a zyxel) has a hard time if the router is rebooted and it loses its mapping, its not smart enough to re-check things so it loses the ability to get calls till I reboot it too. Others are ok.

Richard rich.ms

mruane

420 posts

Ultimate Geek

#66690 10-Apr-2007 06:03

Thanks for the reply

If I read between the lines, what seems to be happening is that the selection of the SIP port (i.e. 5060) is determined by the need to respond (through the firewall) to incoming calls. So, if I need to accept calls, then each ATA device needs to establish its conection on a seperate port so that the incoming calls can be NAT'ed to the correct IP address for each ATA. I currently have all the ATA's connected to each SIP server on the same TCP5060 port and because I cannot NAT to them all, they will not be able to receive incoming calls.

I guess the WAG54GP2 works ok because its two VOIP ports must be on the other side of the firewall and so do not need to be NAT'ed.

Is that about it?

Cheers Mike

richms

28168 posts

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#66724 10-Apr-2007 14:52

No, because calls come in just fine to whatever ata or softphone is dialed. It uses stun to find its external port and ip and uses that in its communication with the sip server, not the internal one. The port on the ata is irrelevent, and theres no need to foward since its udp and stateless it will establish the nat mapping in its communication with the stun server, and keep it open with its constant talking to the sip server with registrations etc. I dont know how it deals with the stateful firewall, but it just does so I dont complain ;)

Richard rich.ms

mruane

420 posts

Ultimate Geek

#66747 10-Apr-2007 20:57

Ah, thanks.

That makes sense to me, thanks for taking the time to explain. It has helped.

Cheers Mike