Two cabinet OS7200 V4.98. 20 SIP Trunks behind a Fortigate 100 firewall. Internet went down this morning around 5:30am. Internet came back up at 7:30am. The IT director had to restart the Fortigate so that all data services would come back up. The SIP services would not re-register after the firewall restart. The alarm log said-ISP1 NOK REG TO

I had to restart the phone system for the SIP to re-register. Any ideas? We are authorizing using log in phone number ID and password.

Will the phone system need to be restarted every time the internet goes down?

MikeS In VA.

Look at the DNS setting in the 7200 system. The system needs to have correct DNS settings to resolve the sip server. Ran into this a few times. After a internet issue, the phone system cannot resolve. Had to reset the sip trunk manually to get it to connect again.

Robert,

Do you mean the DNS settings on the phone system side of things--not the SIP Carrier Options?

Even by manually restarting the SIP service, it would not come up unless the system was restarted.

MikeS in VA

In 4.8x or 4.9x software the way DNS servers are used in sip carrier options changed.

In system options turn on Multi DNS.
This will use the DNS servers in the sip carrier options as well as the DNS servers in System IO paramaters.

That error you got translates to:

"System tries to register to the server but it can’t receive response message."

Ie the message back from the provider didn't get to the system

Yes Mike, 5.6.1 At the bottom of the page. This usually gets the sip trunks to automatically register after a network error. If that doesn't work, something on the network might be blocking the communications.

Rob, Steven,

I have 8.8.8.8 and 8.8.4.4 programmed in 5.6.1.

OS7200's & 7400's don't offer the multi dns option--just OS7030 & OS7100.

MikeS In VA

You need software version 4.92 or higher to see the Multi DNS options.

Mike is right, the OS7200 and OS7400 don't have a multidns option, only the smaller ones do.

Did you try disabling and re-enabling the sip before a reboot?

I have had to occasionally reboot systems to get sip working, but only the OS7100.

I don't believe this was a DNS issue.

You can test fairly easily, just put the ip address of the proxy server in the outbound proxy, and the dns name in proxy domain name.

Eg
outbound proxy 1.2.3.4
proxy domain name sipcarrier.org

I think the system and the fortigate had an issue, a wireshark trace next time it happens will likely shed some more light.
It's one of the things i really like about the SCM having inbuilt traces.

Thanks Steven. Thanks all.

MikeS In VA