[Sipp-users] Understanding loops and conditions in UAC scenario with SIPp

[Joel S. <jo...@go...>]

Hi everybody,

I'm new to the list. I'm trying to create a simple scenario with SIPp but
I'm running into the following problem:

During an active call, the UAC might receive a MESSAGE request from the UAS
and it has to answer with a 200 OK to that MESSAGE.

This can happen X times.

Also, it is possible that the BYE comes from the UAS, we have to consider
that option too.

With my current config, I get a message when the script starts that says
"<recv> before <send> sequence without a mandatory message. Please remove
one 'optional=true'..."


SIPp UAC             Remote UAS
    |(1) INVITE            |
    |--------------------->|
    |(2) 100 (Optional)    |
    |<---------------------|
    |(3) 180 (Optional)    |
    |<---------------------|
    |(4) 183 (Optional)    |
    |<---------------------|
    |(5) 200               |
    |<---------------------|
    |(6) ACK               |
    |--------------------->|
    |                      |
    |(7) MESSAGE (Optional)|  -----+
    |<---------------------|       |
    |                      |       +---- Loop until I get a BYE
    |(8) 200 (Optional)    |       |
    |--------------------->|  -----+
    |                      |
    |(7) BYE               |  -----+
    |<-------------------->|       |
    |                      |       +---- The BYE can be sent from the UAC
or the UAS.
    |(9) 200               |       |
    |<-------------------->|  -----+



My scenario.xml is the as follows:


<scenario name="Test UAC">
  <send retrans="500">
    <![CDATA[
      INVITE [...]
    ]]>
  </send>

  <recv response="100" optional="true">
  </recv>

  <recv response="180" optional="true">
  </recv>

  <recv response="183" optional="true">
  </recv>

  <recv response="200" rtd="true">
  </recv>

  <send>
    <![CDATA[
      ACK [...]
    ]]>
  </send>

  <recv request="MESSAGE" optional="true">
  </recv>

  <send>
    <![CDATA[
      SIP/2.0 200 OK
      [last_Via:]
      [last_From:]
      [last_To:];tag=[call_number]
      [last_Call-ID:]
      [last_CSeq:]
      Content-Length: 0
    ]]>
  </send>

  <pause/>

  <send retrans="500">
    <![CDATA[
      BYE [...]
    ]]>
  </send>

  <recv response="200" crlf="true">
  </recv>

  <ResponseTimeRepartition value="10, 20, 30, 40, 50, 100, 150, 200"/>

  <CallLengthRepartition value="10, 50, 100, 500, 1000, 5000, 10000"/>

</scenario>

I run the script with:

sipp -d 20000 -s *52 X.X.X.X:5060 -r 1 -l 1 -m 1 -trace_msg -trace_err -i
public_ip -sf scenario.xml -inf database.csv


I have read the conditional branching documentation:

http://sipp.sourceforge.net/doc/reference.html#branching

I have also found this previous post in the list with a similar problem:

http://sourceforge.net/p/sipp/mailman/message/9014449/


So for the MESSAGE I think I have to play with the next and label
parameters, but I have tried several combinations and I can't get it to
work.

For the BYE being able to come from UAC if timeout is reached or from UAS
before the timeout is reached is another problem I don't know how to handle.

If there is any more documentation I have missed that can help me figure
this out I would be more than welcome to read it.

All help/comments are appreciated.


Thanks in advance.

Best regards,
Joel.