Cannot send RTP by SIPp tool

Question

I am trying to replay an captured pcap file with sipp as follows:

In Sending.xml

...

<recv response="200" rrs="true">
<action>
<ereg regexp="(.*)" search_in="hdr" header="To:" assign_to="TO_REQUEST"/>
</action>
</recv>

<send >
<![CDATA[
ACK [next_url] SIP/2.0
To: [$TO_REQUEST]
From: [$FROM_REQUEST]
Via: SIP/2.0/[transport] [local_ip]:[local_port];branch=[branch]
Call-ID: [call_id]
CSeq: [last_cseq_number] ACK
Contact: <sip:[local_ip]:[local_port]> 
[routes]
Max-Forwards: 70
Subject: Performance Test
Content-Length: 0
]]>
</send>

<nop>
<action>
<exec play_pcap_audio="pcap/g711a.pcap"/>
</action>
</nop>

...

However, I always get the same error: extract_rtp_remote_addr: no IP address found in SDP message body.

I tried to test with other *.pcap and *.raw files and edit my script but I still cannot. When I only send the signal not RTP, the call is successful.

Anyone can help me send RTP by SIPp? Thanks in advance!

Answer 1

I recall I had similar issues with that at some point due to my .pcap not being very 'clean'.

Are you sure the pcap contains just the RTP packets and nothing else?

For a working example of pcap played by sipp, you can check webrtc-test project and more specifically: .pcap and relevant sipp xml

Also notice that sipp usually only plays just one direction of the RTP media, so it's best if you have media flowing in both directions to make sure.

Hope this helps.

Best regards, Antonis Tsakiridis

Answer 2

This may have to do with the SDP in your INVITE. extract_rtp_remote_addr will be looking for an IP address to send the RTP to.

Check your INVITE in the XML has the correct IP address in the c line.