This software works with Asterisk. You can use Nortel i2002, i2004 and i2050 phones with PSTN/ISDN/E1/T1 lines and SIP/H.323/Cisco compatible phones. You can obtain more informations about Asterisk at Voip-info.org. Documentation about this channel driver can be found in chan_unistim tarball and wiki asterisk + unistim. Asterisk runs on Linux, BSD and OSX.