Hi

We use a resolver plugin to determine our sip messages. We have already a release on the field and want to do some adaptions and to assure backwards compatibility. The current version uses two media description fields. The first one is for the old media type (application), the new one resolves audio. The new resolver looks like:

<SDP_LINES>
<LINE name="m" value="application 0 UDP TCG">
<LINE name="m" value="audio 0 RTP/AVP 18">
</SDP_LINES>

The m-content of the SIP Message looks like:

Media Description, name and address (m): application 18778 udp TCG
Media Description, name and address (m): audio 18778 RTP/AVP 18 97

The problem is now the backwards compatibility. The old resolver supports only the first SDP_LINES:

<SDP_LINES>
<LINE name="m" value="application 0 UDP TCG">
</SDP_LINES>

If now an INVITE with the mentioned SDP m-part has been received, it will be discarded.

Is this the normal behavior of the resolver capabilities when there are more media descriptions than expected?
This would mean that backwards compatibility is a general problem. Are there any possibilities to bypass the resolver or is there something wrong and it should technically work?

Thanks and regards,
Cloooned