Incoming call: Got SIP response 500 "Internal Server Error" back from


I’ve an Asterisk version 1.29, that has been working well for years till now, but suddenly started to receive a lot of these messages:

Incoming call: Got SIP response 500 “Internal Server Error” back from XXX.XXX.XXX.XXX

The IPs belong all to extensions that are registered in this server and can do and receive calls without any problem.

How can I fix/deactivate (if this is the case) these messages, please?

Best regards,

Humberto Andrade

Fix the remote peer. Asterisk is simply reporting that the system to which it tried to forward the call is rejecting it with an error which, at face values, says that, other, system is broken.

Hi David,

Thanks for your reply.

We have no calls rejected…simply the asterisk started to receive these error messages (a lot of ones, all the time),

If the peer isn’t breaking on calls, it will be breaking on REGISTER, or on the OPTIONS requests used to test whether there is still a valid communications path to it (and also to keep firewall and NAT rules alive).

So, what can I do to fix this, please?

If you enable “sip set debug on” and provide the traffic including the 500 Internal Server Error then we can narrow down what exactly we’re sending that it doesn’t like.

sip debug.txt (72.6 KB)

Please can you see the annex?

The chan_sip module is sending NOTIFY messages to the Polycoms to provide information about the availability of extensions. They are responding with the 500 Internal Server Error. Why that is I’m not sure.

Is there any way to configure Asterisk to not send these messages? Or is it convenient to send them?

The phones explicitly subscribe to receive the messages. We don’t (and can’t) push them to the phones against their will.

What’s strange is that I put an Asterisk with version 1.2.31 running for a while (which is in production has version 1.2.29) and these error messages never appeared. Today I put the version 1.2.29 in production again and the problem reappeared and in force … which leads me to believe that it will be more of an Asterisk problem instead of being a terminal problem (Polycom phones)…what do you think?

I don’t know. That version is incredibly old and I don’t remember much specific about it.

OK. Thanks for your help.