Call or registration to ... has failed. 503 Service unavailable.

[Matt Stephens]

This issue started yesterday. Only some numbers we cannot call out to. So far, I have a list of 5 numbers but it seems to keep growing.

The attempt goes from the 3CX Server to our Patton ISDN gateway, the Patton sends back the 503

We can call out to other numbers just fine (my cell phone for example). Also, the numbers that the patton can't reach I can call from my cell phone successfully.

What could be happening?

 Call to T:Line:10000>>1------4113@[Dev:sip:[email protected]:5060] from L:14077.1[Extn:139] failed, cause: Cause: 503 Service Unavailable/INVITE from 192.168.1.30:5060

I took out some of the phone number for privacy, the 192 address is our Patton

EDIT: Looking through the logs, there are at least 10 different numbers now, and they are all local number. Not sure if that's relevant

 

[leejor]

Possibly one of two things...your provider has an issue completing calls to those numbers (failed/blocked trunk at their end?), or, (and less likely unless someone had been tinkering with the Patton), something changed in the Patton, such as a dialplan, allowing some numbers, but not all.

I would speak to your provider and ask if they see a call attempt, from you, on one of the failed calls.

 

[Matt Stephens]

Possibly one of two things...your provider has an issue completing calls to those numbers (failed/blocked trunk at their end?), or, (and less likely unless someone had been tinkering with the Patton), something changed in the Patton, such as a dialplan, allowing some numbers, but not all.

I would speak to your provider and ask if they see a call attempt, from you, on one of the failed calls.

Thanks. I was kind of dreading that answer... haha. I'll get on the phone with them and update here what they say.

 

[leejor]

I'm assuming that all ISDN B channels out of the Patton are not all busy. Some people have an allocation less than the 23 per T1

 

[Matt Stephens]

I have confirmed with the provider (Frontier) that there is an outage in our area.

 

[eddv123]

Quick tip for the future if you ever experience issues again. You can run debugging commands from the CLI of the Patton gateway: https://www.3cx.com/docs/patton-isdn-debugging/

For ISDN (using the command line):

enable
show running‐config
debug call‐router
debug call‐control
debug ccisdn signaling
debug context sip‐gateway signaling detail 5
debug context sip‐gateway transport detail 5
debug context sip‐gateway error

Run the test and then when done enter "no debug all" to stop it running.

These are very detailed and can give you a good idea of the issue before even calling your provider.