First time here? Check out the FAQ!
THIS IS A TEST INSTANCE. Feel free to ask and answer questions, but take care to avoid triggering too many notifications.
Ask Your Question
0

SIP register timeout

Hi all,

I have a fax server running on a Windows Server 2019 machine. The fax server communicates via VoIP and registers itself on a PBX in the local network.

Problem: the fax server sends regularly SIP REGISTER requests to the PBX which results in a time out.

I recorded a trace from the fax server (192.168.73.150) and the PBX (192.168.73.1).

An example:

  • in 192.168.73.150 a REGISTER request is sent (packet no. 310)
  • in 192.168.73.1 I am not able to find the correspondig request. It seems that it didn't even reach it's destination.

Am I missing something? Can you witness my observation?

EDIT There is a successful registration in the fax server trace at 13:46:45 (Packat no. 88). The next registration at 13:47:40 fails as the PBX sends a tcp ack but no SIP response code.

sugar76's avatar
9
sugar76
asked 2019-11-23 13:28:13 +0000, updated 2019-11-26 14:41:04 +0000
edit flag offensive 0 remove flag close merge delete

Comments

add a comment see more comments

1 Answer

0

Looking at the fax server capture the initial SIP registrations (for ext #34 and #35) work as normal.The PBX capture seems to have been started after these successful SIP registrations. This makes it difficult to figure out what's going on. The subsequent SIP requests for options seem to choke the SIP server, which doesn't respond. There are also TLS connections being made, is the SIP registration made there as well?

Jaap's avatar
13.7k
Jaap
answered 2019-11-23 19:54:13 +0000
edit flag offensive 0 remove flag delete link
more

Comments

The TLS connections don't come from the fax server. On the 192.168.73.150 trace, packet no. 34 is a ping reply so I am not sure what you mean by initial SIP registrations (for ext #34 and #35). The SIP Options maybe interesting as in the configuration of the fax server sending of SIP Options is disabled. I will check that.

sugar76's avatar sugar76 (2019-11-24 18:03:08 +0000) edit
more
  • delete

Maybe my first comment was a bit unclear, sorry for that :-) I see a successful registration at 13:46:45 (Packet no. 88-101). You see this on the PBX side at almost the same time. But the next registration at 13:47:40 fails (starting at Packet no 250). The PBX answers with a tcp ack, but sends no sip response with a status code ... Is my observation correct?

sugar76's avatar sugar76 (2019-11-26 14:38:36 +0000) edit
more
  • delete

Your capture file at the PBX side (trace-192.168.73.1-2019-11-23-filtered.pcap) has the following properties:

First packet: 2019-11-23 13:47:01
Last packet: 2019-11-23 13:48:13
Elapsed: 00:01:12

Therefore does not show the SIP registration.

Jaap's avatar Jaap (2019-11-26 17:30:54 +0000) edit
more
  • delete

You are completely right, the capture on the PBX side is incomplete. My fault. I will wait until the problem rises again and then do a complete capture.

sugar76's avatar sugar76 (2019-11-27 08:04:50 +0000) edit
more
  • delete
add a comment see more comments

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account. This space is reserved only for answers. If you would like to engage in a discussion, please instead post a comment under the question or an answer that you would like to discuss.

Add Answer