Attention is currently required from: fixeria, laforge, osmith, pespin.

Hello Jenkins Builder, fixeria, laforge, osmith,

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

https://gerrit.osmocom.org/c/osmo-mgw/+/36633?usp=email

to look at the new patch set (#4).

Change subject: mgcp-client: always send 'm=audio' line ......................................................................

mgcp-client: always send 'm=audio' line

Re-add the m=audio line to SDP emitted from libosmo-mgcp-client, even if the audio port is not set yet

Patch a5acaa68db4cc26e342069ad2ef37c1b09e1efc2 introduced a presence flag for the RTP audio port number. This flag, when unset, also omitted the 'm=audio...' line completely, dropping the PT number definitions.

Correct:

m=audio 1234 RTP/AVP 96 <--- anounce 96 a=rtpmap:96 VND.3GPP.IUFP/16000 <--- further specify 96 a=fmtp:96 ... <--- further specify 96

When m=audio is missing, we only have orphaned rtpmap and fmtp entries. They are supposed to further specify the 96 listed in 'RTP/AVP 96', instead they are without context:

a=rtpmap:96 VND.3GPP.IUFP/16000 a=fmtp:96 ...

When the presence map indicates no port known, we still need to emit the list of PT numbers; so we're forced to send a port of 0:

m=audio 0 RTP/AVP 96 a=rtpmap:96 VND.3GPP.IUFP/16000 a=fmtp:96 ...

This is an important fix for osmo-hnbgw, which sends the first CRCX with an IUFP codec, at a time when the remote port is not yet known. osmo-mgw requires an m=audio line to accept incoming IuUP Initializaition requests. When m=audio is missing, osmo-mgw does not parse the IUFP codec, and 3G voice fails completely. This mgcp-client patch will emit valid codec config also when port == 0, fixing osmo-hnbgw voice, because osmo-mgw will know about IUFP from the start.

Related: SYS#6907 SYS#6974 Related: osmo-mgw a5acaa68db4cc26e342069ad2ef37c1b09e1efc2 Change-Id: Id95b629453aec999100b5af821c6a0b9562bb597 --- M src/libosmo-mgcp-client/mgcp_client.c 1 file changed, 55 insertions(+), 6 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/osmo-mgw refs/changes/33/36633/4