Network connection to ruby daemon script connect on public ip of local machine but fails remotely

On a Mac OSX 10.5.8 server OS,
% ruby sip-alg-detector-daemon.rb -i
Mon Nov 21 00:16:46 2011 INFO: Starting SIP ALG Detector daemon…
Mon Nov 21 00:16:46 2011 INFO: Use ‘-i IP’ to set the listening IP
Mon Nov 21 00:16:46 2011 INFO: Use ‘-p PORT’ to set the listening port
Mon Nov 21 00:16:46 2011 INFO: Bind address:


Being on the same machine the client sip-alg-detector.rb and telnet
connect both OK to sip-alg-detector-daemon.rb on port 5060.
% ruby sip-alg-detector.rb -n -si -lp 5065


Being on a remote Mac OSX 10.6.8 machine, the client is unable to
connect to the remote port 5060, not TCP neither UDP, also telnet fails:
telnet: connect to address Operation timed out
telnet: Unable to connect to remote host


Step already tried to resolve…

  1. Check server firewall
    The ipfw firewall accepts the packets:
    Nov 21 02:31:07 193 ipfw[892]: 12323 Accept TCP in via en0

  2. Check client firewall
    Firewall disabled, result = identical

  3. Check from another host returns a “stealth” on port 5060


What kind of “magic” is required on Mac OSX to make this ruby daemon on
port 5060 to become connectable from remote networks?

% ruby -v
ruby 1.8.6 (2009-06-08 patchlevel 369) [universal-darwin9.0]

% uname -a
Darwin 9.8.0 Darwin Kernel Version 9.8.0: Wed Jul 15 16:55:01
PDT 2009; root:xnu-1228.15.4~1/RELEASE_I386 i386