[cisco-voip] Authenticating using ip address and MAC address from TCL IVR 2.0

[vignesh]

Hello all
I am using TCL ivr 2.0 and free radius 1.1. I want to authenticate users
based on their ip address and MAC address. I searched on the net but
couldn't get any example on how to retrive the MAC address. If I want to
authenticate the users by their MAC address then what are the changes
that I have to do. Because I don't see the mac address in the access
reqest. 
Is there a way by which I can retrive the MAC address from the TCL ivr
script

Thanks
Vignesh