Change in osmo-mgw[master]: Take into account Marker bit when patching RTP stream

pespin gerrit-no-reply at
Wed Jul 7 12:15:51 UTC 2021

Hello Jenkins Builder, 

I'd like you to reexamine a change. Please visit

to look at the new patch set (#2).

Change subject: Take into account Marker bit when patching RTP stream

Take into account Marker bit when patching RTP stream

On a deployed osmo-mgw with RTP traffic coming from a thirdparty
RTP source, it was usual to see log messages like following one from
time to time:
"The input timestamp has an alignment error of 159 on SSRC"

Doing a quick traffic analysis showed that the above mentioned RTP
source was generating traffic from time to time containing RTP packets
with the Marker (M) bit.

Those messages were logged because the verification & patching funcions
in osmo-mgw were not Marker-bit aware. Hence, this patch implements
support for Marker bit when handling RTP packets.

The Marker bit is usually used as a start of a talkspurt, and has to be
considered a syncrhonization point, where timestamp and relation to real
time don't need to match with last received RTP packet in the stream.

Related: SYS#5498
Change-Id: I1fb449eda49e82607649122b9b9d983a9e5983fa
M include/osmocom/mgcp/mgcp_network.h
M src/libosmo-mgcp/mgcp_network.c
M tests/mgcp/mgcp_test.c
M tests/mgcp/mgcp_test.ok
4 files changed, 90 insertions(+), 20 deletions(-)

  git pull ssh:// refs/changes/72/24872/2
To view, visit
To unsubscribe, or for help writing mail filters, visit

Gerrit-Project: osmo-mgw
Gerrit-Branch: master
Gerrit-Change-Id: I1fb449eda49e82607649122b9b9d983a9e5983fa
Gerrit-Change-Number: 24872
Gerrit-PatchSet: 2
Gerrit-Owner: pespin <pespin at>
Gerrit-Reviewer: Jenkins Builder
Gerrit-MessageType: newpatchset
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the gerrit-log mailing list