[asterisk-users] RTP Timestamp rewind

Mark Wiater mark.wiater at greybeam.com
Tue Aug 29 13:38:29 CDT 2017

Hi folks.

I have a couple of questions regarding RTP.

The background of my inquiry is that I have packet captures of SIP and
RTP traffic on an Asterisk and Broadworks SIP trunk and the RTP many
times has a time stamp that rewinds by 480 using g.711u. The Sequence
number continues to increment appropriately, but the timestamp just rewinds.

It doesn't happen on every call, but it's frequent enough to make me
want to understand it better.

My questions are:

Is there ever a circumstance where it would be normal or logical to see
the RTP timestamp go backwards during the RTP stream?  Consistently by
480, 3 voice frames?

Will Asterisk just drop the packets that compromise the rewind?



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.digium.com/pipermail/asterisk-users/attachments/20170829/4eef3c58/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: nofgcbcgfipggiec.png
Type: image/png
Size: 8550 bytes
Desc: not available
URL: <http://lists.digium.com/pipermail/asterisk-users/attachments/20170829/4eef3c58/attachment.png>

More information about the asterisk-users mailing list