Summary:ASTERISK-18749: (Only) First attempt to put a call on hold fails when using SRTP
Reporter:Birger "WIMPy" Harzenetter (wimpy)Labels:
Date Opened:2011-10-24 07:47:15Date Closed:2012-01-17 11:04:06.000-0600
Versions:SVN Frequency of
is related toASTERISK-18859 Unable to place calls from some SIP phones ("Multiple audio streams are not supported")
Environment:Attachments:( 0) sipdebug
Description:When using SRTP, the first attempt to put a call on hold fails with 488 so the other end hears silence instead of MOH.
After retrieving the call, further attempts to put it on hold, work as expected, however.
Comments:By: Birger "WIMPy" Harzenetter (wimpy) 2011-10-24 07:48:14.658-0500

sip debug of a call with one failed and two successful hold attempts

By: Birger "WIMPy" Harzenetter (wimpy) 2011-11-14 12:58:21.072-0600

This seems to be the same effect as in ASTERISK-18859
The solution is to not set RTP/SAVP to off or optional on Snom phones.
Setting it to mandatory fixes the issue.

By: Joshua C. Colp (jcolp) 2012-01-17 10:53:50.164-0600

After examining the provided sip debug trace I have confirmed that indeed this issue is caused by optional SRTP just like ASTERISK-18859. Asterisk does not currently support optional SRTP. All SIP endpoints must either have SRTP set to be mandatory or disabled.