Summary:ASTERISK-16503: chan_mgcp does not send CRCX with SDP
Reporter:Tim Gruenberg (tgruenberg)Labels:
Date Opened:2010-08-04 09:19:51Date Closed:2021-08-12 09:48:20
Versions:Frequency of
Environment:Attachments:( 0) myDebugLog
( 1) myDebugLog.txt
( 2) myDebugLog-IAX-Call
( 3) myDebugLog-IAX-Call.txt
Description:If a call from Asterisk to an MGCP endpoint is initiated, the CRCX (CreateConnection) does not include a SDP part. So Asterisk says on console BUSY!

I've tested this with a patched Asterisk patched with ncs-packetcable-minus273-1424.patch. In this case the Asterisk sends with the CRCX message an SDP part.

I can send 2 wireshark traces in, one with working MGCP and one with not working MGCP.
Comments:By: Tim Gruenberg (tgruenberg) 2010-08-04 09:21:16

From MGCP endpoint to Asterisk there is no problem

By: Leif Madsen (lmadsen) 2010-08-05 15:38:04

You have this marked as 1.8.0-beta2 but your description says 1.4.24 + patches.

We can't support a version of Asterisk that old, or with patches associated with it.

Please test with a vanilla Asterisk version that is recent, and at that point we may be able to move this issue forward.

By: Tim Gruenberg (tgruenberg) 2010-08-06 00:37:18

This is right, the problem is on 1.8.0-beta2 a successfull test I've made with 1.4.24.

My report is for 1.8.0-beta2.

By: Tim Gruenberg (tgruenberg) 2010-08-06 00:39:23

1.8.0-beta2 is patched with 0017743 patch in cause of the crash of the asterisk.

By: Paul Belanger (pabelanger) 2010-08-18 08:29:36

We require a complete debug log to help triage the issue.

This document will provide instructions on how to collect debugging logs from an Asterisk machine for the purpose of helping bug marshals troubleshoot an issue:


By: Tim Gruenberg (tgruenberg) 2010-08-24 01:23:29


both debug logs show a call to a DOCSIS eMTA, one from the asterisk console, and one from an IAX2 connection, I hope this will help you to figure out the issue.

By: Matt Jordan (mjordan) 2013-01-15 11:24:33.406-0600

{{chan_mgcp}} is an extended support module, and as such, development support for it comes primarily from the open source community. Patches would be welcome for all issues - but especially for extended support modules.

By: Sean Bright (seanbright) 2021-08-10 12:51:39.280-0500

Logs re-attached with .txt extension

By: Sean Bright (seanbright) 2021-08-10 12:58:17.643-0500

[~tgruenberg], are you still able to reproduce this in a supported version of Asterisk (16+ at the time of this message)?

By: Tim Gruenberg (tgruenberg) 2021-08-12 09:11:12.858-0500

I'm sorry, I've no chance to test this again, I've no access to the equipment needed for the test.

By: Sean Bright (seanbright) 2021-08-12 09:48:20.092-0500

No problem. If anyone is able to reproduce this problem on a [supported version of Asterisk|https://wiki.asterisk.org/wiki/display/AST/Asterisk+Versions], commenting on this issue will re-open it.