cannot make outgoing call

Hello,

We have 3 phones - 2 of which we can make and receive both extension calls and outgoingincoming calls.

We added a SNOM 820 - extension to extension is good, incoming calls are working but we cannot make an outgoing call. -- After dial tone - there is no sound after you dial the numbers - we looked at the last portion of the sip trace - it keeps repeating the invite section - only stops after we cancel the call...Any help would be appreciated. Thanks !

RE: cannot make outgoing call

Based on the assumption the Snom 820 is behind a firewall, then the inbound SIP packets don't seem to reach it selectively. If you used the Snom's built-in SIP trace, following the Invite it should be getting a "407 Proxy Authentication Required", in order for the Snom's SIP stack to send another Invite including the Digest information.

If the Snom gets the 407 message for extension to extension calls which proceed normally, but it doesn't get it for calls destined for an ITSP's trunk, then you might need to look at what is arriving on the WAN side of the router.

Looking at this from a different perspective:
• What does the SIP Trace facility -found at the System Log section- indicate?
• Is PBXes replying to the initial Invite requests from the Snom?

Based on your description, It does for extension to extension calls, but does not for PSTN (ITSP bound) calls.

I doubt the firewall in your router or some other firewall in your network, blocks SIP packets selectively. But since stranger things have happened, it's worth setting up packet traces at several places in your network to verify that.

RE: cannot make outgoing call

Thanks for the quick response. This problem was eventually fixed by downgrading the unit to a previous software version - Thanks Again

RE: cannot make outgoing call

Allow me to say, that downgrading the firmware of a SIP UA, is neither a solution nor a fix.

Eventually you will be required to upgrade it again, and have to face the same issue once again. Unless you let Snom know what was wrong, this issue will never be fixed.

Snom is pretty good in fixing bugs, once they are reported and documented by their users, so taking the easy way out is not the recommended path for this.

Have a nice day.

RE: cannot make outgoing call

Thanks - I will report the problem to SNOM...