Rem Etxs: Call in OK, but can’t receive

[uspnetworks]

We can set up a SNOM320 so that one line works fine on the epygi LAN address, another line is set up to use another gateway to reach the epygi WAN address so we can test remote extension settings.


Both register OK on the epygi.


The LAN address connection works with all expected features. The WAN address can call in, but cannot receive calls from the Quadro.


The phone uses static IP to call out to the WAN address.


We've spent days trying to figure this out.


Any suggestions..?

[davrays]

What do you mean saying "cannot receive calls from the Quadro"? - lets say, you enabled remote extension on ext 15. What does system tell you, when you are dial "15" from any other Quadro extension?

[uspnetworks]

We get a range of responses from temporarily unavaialble to silence. And sometimes it works for reasons we cannot yet trap in the logs. However, we are now waiting to change the router as we believe that switching to Zyxel 662HW may fix some of these problems.

[davrays]

yep, I also think you have network connectivity problem there. Not sure it is specific hardware problem. Rather it is configuration issue.


Connections, which are initiated from the Snom (like registration and calls to Quadro), are ok. And the connections in opposite direction are not established... This could be if you have NAT or firewall enabled on the gateway which Snom uses to connect as remote extension. That gateway may be blocking theconnection attemptsfrom Quadro to Snom.

[uspnetworks]

Well, after a lot of time spent messing with Zyxel routers and updating firmware until we were blue in the face, we concluded that the 662HW was never going to work reliably with any variation of NAT, due to problems with session mappings.

So we set it up as non-NAT and put the public address on the Quadro directly, and it mostly works. We are still chasing down some issues with some remote extensions that live behind NAT/firewalls.

A searchable list of known-working hardware configurations and a list of known "not-working" configurations could save a lot of people a lot ot toime and trouble.