1.1. SIPp doesn't send the messages back to the correct SIP proxy port

By default, SIPp will answer to SIP messages on the same socket where it received the messages. This behavior is a problem for SIP proxies that expect messages on a predifined IP port.
Using the "-rsa" option on the command line allows you to force the address used to send messages and override this default behavior.

1.2. How to automate scenario execution and collect pass / failed results

You don't need to modify SIPp sources to do that. All you need to do is run one call, exit (using -m command line option) and test the return code, as specified in SIPp help:
Exit code:

Upon exit (on fatal error or when the number of asked calls (-m option) is reached, sipp exits with one of the following exit code:
0: All calls were successful
1: At least one call failed
99: Normal exit without calls processed
-1: Fatal error

A shell script could look like:

ocadmin@idefix:~/OJA/sipp.2004-09-21$ cat run.sh
#!/bin/sh
>results.txt
for i in $*
do
  echo Launching test $i >> results.txt
  ./sipp -sf $i -m 1 127.0.0.1
  if test $? -ne 0
    then
        echo Test $i failed >> results.txt
    else
        echo Test $i succeeded >> results.txt
    fi
done
exit 0
ocadmin@idefix:~/OJA/sipp.2004-09-21$

Launch the tests: ./run.sh *.xml
Then you will get a result file like this:

ocadmin@idefix:~/OJA/sipp.2004-09-21$ cat results.txt
Launching test regexp.xml
Test regexp.xml failed
Launching test uac.xml
Test uac.xml succeeded
ocadmin@idefix:~/OJA/sipp.2004-09-21$

2.1. How can I help write documentation?

This project uses Apache Forrest to generate documentation from XML. Please download a copy of Forrest, which can be used to validate, develop and render a project site.

Documentation sources (XML files) are available on request (ojacques@users.sourceforge.net).