PRI Failure Signal to SIP Trunk

[gregh]

Anyone know of a way to automatically shutdown a SIP Trunk when the PRI goes down on a 908e?

This would be a failover scenario where a PRI failure brings down the SIP trunk so that the SIP server could reroute calls.

[gregh]

A different but related way of asking the question:

Is there a mechanism within the 908 that sends a SIP message to the SIP server upon loss of PRI connectivity?

[Anonymous · Accepted solution]

With most SIP servers you should be able to route advance on failure.

The TA908e sends back a 5XX error when the PRI goes down.

[gregh]

Thanks unified, that's what I was looking for.

I assumed that the 908 would send some sort of message on a PRI failure but could not find definitive documentation as to what that message would be.

[Anonymous]

Hello Greg,

I will add to what unified said.  If you do not like the SIP message being sent back to the sip server when the PRI is down, you can change the cause codes.  In the CLI, the command looks like this:

voice cause-code-map from-pri <pri cause code> <sip message>

For example, if you were getting isdn cause code 27 (destination out of order) and the ADTRAN was sending a 502 BAD GATEWAY, you could change that if you wanted:

voice cause-code-map from-pri 27 <sip message>

Regards,

Geoff

[gregh]

Thanks Geoff,

That's awesome information. I had now idea that we had that level of control. Not sure I would want to make those types of changes but good to know we have the option.

[Anonymous]

Thanks Geoff that is definetly good information and I am adding it to my list of useful Adtran commands.

John Wable

[Anonymous]

Geoff,

    Is there a list anywhere of the 127 cause codes?

John Wable

[Anonymous]

Answering my own question.  I found it at the following website: ISDN Cause Codes

This site has the PRI to SIP default mappings at least for Dialogic devices Cause Code Mappings - ISUP to SIP can anyone verify if these mapping match Adtran Mappings?

Message was edited by: jwable

[Anonymous]

Hello John,

If you do a show run voice verbose, you can see the SIP to PRI and PRI to SIP cause codes mappings in the ADTRAN.

Regards,

Geoff

[Anonymous]

Geoff,

    Thanks.

John Wable

[Anonymous]

Just to add one more thing to this conversation, the specific cause code for a PRI interface being down is 41. The ADTRAN by default responds with a "503 Service Unavailable" if the PRI interface is down. If you would like for the ADTRAN unit to respond with something else, you can change the cause code map "from-pri" for cause code 41. For example, if you wanted the ADTRAN to send a "500 Server Internal Error" instead of "503 Service Unavailable", you would add the following configuration: voice cause-code-map from-pri 41 500