Sending BYE to wrong Branch


Hi, I ran into an issue with our freepbx install and AnveoDirect.
We use
FreePBX with Asterisk 13.38.1 built by mockbuild @ jenkins7 on a x86_64 running Linux on 2020-12-23 15:21:33 UTC

the system works pretty stably, has been for a couple of years. We have been using Anveodirect all this time.
Today I noticed we had a few calls that were several hours long so I contacted them to let them know we had been overbilled, but they responded with images of their SIP logs where they tell me 2 things

  1. that our server sent them the BYE message to the wrong branch address and therefore responded with a 501 and let the call continue, even though our server clearly had ended the call (in our CDR)
  2. that our side is not including the TAG after the SIP TO line.

our low-level config is pretty standard. We use pjsip for most everything except for anveodirect for which we use chansip with port 5160. And the sip settings for anveo are copy/pasted from their FAQ.

Anybody have any idea where I should start looking to figure these two things out?

(David55) #2

You need to use “pjsip set logger on” to verify what they are saying. I find it difficult to believe that (2) is true, and I don’t see where it could have got a wrong branch parameter from (I assume that is what they mean by branch address). The branch parameter is a unique, but random, identifier.

The branch parameter on the BYE should be different from any other branch parameter on a request, so the only way it could be wrong is if it was being reused.

501 is not a valid response to a BYE, as it means their server never accepts BYE. 501 is method non known, and all SIP servers that support calls need to know about BYE.

As a technical point, anything that is sending BYE is a client, in SIP terms, at the time it is doing it.


So it seems it is indeed broken, but caused by a space send as part of the dial string. How or why it breaks I have no idea, but the calls where this happened all have a space separating the country and city code.
thank you for your explanation of how to look further into this.

(system) closed #4

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