/usr/share/doc/libnet-sip-perl/examples/bin/answer_machine.pl.gz
/usr/share/doc/libnet-sip-perl/examples/bin/nathelper.pl
/usr/share/doc/libnet-sip-perl/examples/bin/README
/usr/share/doc/libnet-sip-perl/examples/bin/stateless_proxy.pl.gz
You may install this package on Debian with
apt-get
install libnet-sip-perl