I am trying to go use SIPp head to head UAS/UAC and echo the RTP from the UAC on each call. -Both UAS and UAC scenario have auto_media_port in m line.
-If I run the scenario with one simultaneous call, the test completes properly with UAS echoing all RTP -If i run the scenario with more than one simultaneous call, the first call completes with proper RTP echo and the +N simulation calls do not have their RTP echoed by the UAS.

-Using SUSE package of 3.3 as I had compiling issues I was not able to resolve with newer verions. Preliminary testing with 3.5 on Ubuntu yieled similar results. SuSe-Outside:~ # sipp -v SIPp v3.3-TLS-SCTP-PCAP, built Jun 23 2013, 00:25:41.

Start UAS with sipp -t u1 -mi 10.19.27.99 -i 10.19.27.99 -p 5060 -mp 16384 -rtp_echo -sf /root/scripts-sipp/uas-01-00.xml

Start UAC with sipp -t u1 -r 1 -l 2 -m 2 -i 172.16.209.100 -p 5060 -s 5552371111 -mi 172.16.209.100 -mp 22000 -sf /root/scripts-sipp/uac-02-00.xml 10.19.27.99

UAS stats indicate first RTP was echoed, 2nd was not

UAS

------------------------------ Scenario Screen -------- [1-9]: Change Screen -- Port Total-time Total-calls Transport 5060 58.12 s 2 UDP

0 new calls during 1.001 s period 1 ms scheduler resolution 2 calls Peak was 2 calls, after 52 s 0 Running, 3 Paused, 3 Woken up 0 dead call msg (discarded) 3 open sockets 317 Total echo RTP pckts 1st stream 8.592 last period RTP rate (kB/s) 0 Total echo RTP pckts 2nd stream 0.000 last period RTP rate (kB/s)

                             Messages  Retrans   Timeout   Unexpected-Msg

----------> INVITE 2 0 0 0

<---------- 180 2 0 <---------- 200 2 0 0 ----------> ACK E-RTD1 2 0 0 0

----------> BYE 0 0 0 0 <---------- 200 0 0 [ 4000ms] Pause 0 0 ------------------------------ Sipp Server Mode -------------------------------

UAC stats ------------------------------ Scenario Screen -------- [1-9]: Change Screen -- Call-rate(length) Port Total-time Total-calls Remote-host 1.0(0 ms)/1.000s 5060 17.04 s 2 10.19.27.99:5060(UDP)

Call limit reached (-m 2), 1.001 s period 1 ms scheduler resolution 2 calls (limit 2) Peak was 2 calls, after 2 s 0 Running, 3 Paused, 4 Woken up 0 dead call msg (discarded) 0 out-of-call msg (discarded) 3 open sockets 1555 Total RTP pckts sent 17.355 last period RTP rate (kB/s)

                             Messages  Retrans   Timeout   Unexpected-Msg
  INVITE ---------->         2         0         0
     100 <----------         0         0         0         0
     180 <----------         2         0         0         0
     181 <----------         0         0         0         0
     183 <----------         0         0         0         0
     200 <----------  E-RTD1 2         0         0         0
     ACK ---------->         2         0
   Pause [      0ms]         2                             0
          [ NOP ]
   Pause [     7:12]         2                             0
     BYE ---------->         0         0         0
     200 <----------         0         0         0         0

Packet capture shows RTP originated by UAC for 2nd stream arriving at UAS on IP and port that was sent in SDP on the 2nd call setup.

UAS SuSe-Inside:~ # netstat -lnp | grep sipp udp 0 0 10.19.27.99:5060 0.0.0.0:* 25460/sipp udp 0 0 10.19.27.99:16384 0.0.0.0:* 25460/sipp udp 0 0 10.19.27.99:16386 0.0.0.0:* 25460/sipp udp 0 0 0.0.0.0:8888 0.0.0.0:* 25460/sipp

UAC SuSe-Outside:~ # netstat -lnp | grep sipp udp 0 0 172.16.209.100:5060 0.0.0.0:* 27756/sipp udp 213248 0 172.16.209.100:22000 0.0.0.0:* 27756/sipp udp 0 0 172.16.209.100:22002 0.0.0.0:* 27756/sipp udp 0 0 0.0.0.0:8888 0.0.0.0:* 27756/sipp raw 213248 0 0.0.0.0:17 0.0.0.0:* 7 27756/sipp raw 213248 0 0.0.0.0:17 0.0.0.0:* 7 27756/sipp

What it looks like is, on the UAS, SIPp is only listening for UDP/RTP on the first advertised port in SDP (and SDP+2) and not opening another socket for the 2nd simultaneous call.

What I am not clear on is if I'm causing this problem with an incorrect command line flag, bad scenario, or otherwise.

Any additional insight on how I might be able to isolate this problem as well as any known limitations of -rtp_echo would be appreciated.

Thanks, J