If the phone supports provisioning then you could probably use the phone's MAC address as a filename and have your box to generate a config file on the fly that way. And yes, Ken is right on this one, a MAC address is really meant for the link local network, not the WAN as most people think it is. From: freeswitch-users-bounces@lists.freeswitch.org [mailto:freeswitch-users-bounces@lists.freeswitch.org] On Behalf Of Ken Rice Sent: Thursday, July 4, 2013 8:41 AM To: FreeSWITCH Users Help Subject: Re: [Freeswitch-users] SIP Trunking No... The MAC address on the wire would not actually be the mac address from the phone if the there is a router between the phone and the server, and if the mac address were embedded in the SIP messages it would be easy to spoof so this is sorta useless for validating where the traffic came from (plus MAC addresses are way easy to spoof, most network card drivers allow you to actually specify the MAC you want to use as a setting) On 7/4/13 2:27 AM, "Ashwin Jain" <ashwinrkjain@gmail.com> wrote: Is there anyway in which we can authenticate SIP phones based on MAC addresses? -- Ken http://www.FreeSWITCH.org http://www.ClueCon.com http://www.OSTAG.org irc.freenode.net #freeswitch