SIP Trunks and Clients on a Mitel 3300

[ralph]

Just wanted to see if anyone is playing with SIP on the Mitel.
Such as using a SIP client accross a VPN or SIP trunks to a carrier.

Something I'm trying to get my head around is how to set up SIP clients back to the 3300.
This I believe would require some type of Session Border Controller to work around firewall issue but it would seem to me if this could be done, you would have a Teleworker Solution / softphone solution w/o having to worry about a Teleworker server.

I have a thought in the back of my mind what could be done but at the moment it's too half baked to post.
Anyone working/playing with this?

Ralph

[Chakara]

  The only SIP I've done was to a Quick Conference server so obviously well documented and easy.  Tuesday I'm going to try to do SIP trunks to an Exchange server for Unified Messaging.  Should be fun, the Mitel docs are good at showing how to set up the Mitel side, but seem to lack sorely on the Exchange side of this setup...

We will see....

  More directly to your questions, I know there are vendors with what I think of as SIP translator type boxes - in theory to may X SIP talk to Y SIP easily.  Haven't played with it though....

-Chak

 

[chadmaynard]

A late reply, but the information might help googlers:

You can easily setup 1:1 NAT/PAT on a border firewall to handle a *single* concurrent SIP conversation at a time with any old NAT firewall. You wouldn't want the filter to rewrite source ports though which is common (and sometimes the only way) on cheaper firewalls. That's why I recommended 1:1 NAT. This usually implies that there is no port mapping. If you need multiple concurrent sessions flowing through the firewall you need a SIP proxy (see http://sourceforge.net/projects/siproxd/ ). The proxy will listen on your SIP port and maintain sessions at the application layer (this is the control a L3 firewall lacks). I have written a SIP proxy in C and put a few softphones behind it just for fun. It is trivial to implement.

A VPN (you mean site to site or road warrior?) doesn't need a proxy since there is typically no address translation.

I won't address outbound SIP connections since they will just work.

[bluewhite4]

We're currently doing both. We have 10 SIP trunks through Bandwidth.com that work perfectly and weren't that hard to setup. Then we also have a SIP analog FXO device that works perfectly, even has a message waiting indicator that works. Then we have 5302 I believe that is technically SIP not MINET (although the new 5304 will be MINET and is basically the same but with a display.)