I would of thought that ISDN would be the perfect solution and if not settle for a standrad POTS line and use one of the folloing; http://www.tieline.com/ http://www.glensound.co.uk/GS-MPI004%20Broadcasters%20Mobile%20Phone.htm http://www.pots.audiotx.com/ http://www.sonifex.co.uk/codecs/index.shtml -----BEGIN GEEK CODE BLOCK----- Version: 3.1 GIT/MU/U dpu s: a--> C++>$ U+> L++> B-> P+> E?> W+++>$ N K W++ O M++>$ V- PS+++ PE++ Y+ PGP t 5 X+ R- tv+ b+> DI D+++ G+ e(+++++) h--(++) r++ z++ ------END GEEK CODE BLOCK------ -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20090326/6fb298bc/attachment-0005.html>