hi,
i read the onsip.org getting started manual.
i tried again with ser and rtpproxy but i received same errors...
then i decided to try with mediaproxy:
i downloaded ser-0.9.0 (emerged from gentoo portage) and mediaproxy-1.4.2.
i followed this instructions: http://www.voip-info.org/wiki-MediaProxy
but i cannot even start it (neither --help works)

$  /etc/init.d/mediaproxy start
: bad interpreter: No such file or directory
and:
$ /usr/local/mediaproxy/mediaproxy.py
: No such file or directory

i got ensured that EOL are not dos-style and i tried that a simple file called test.py (it just prints something) just to make sure that python works...

sorry, i understand it is not properly a ser problem but i don't know where else to ask...
thank you so much!