Freeradius, Nas-Port-ID as username

[Per.H]

We are using the Cisco ACS 5.3 as a RADIUS for database authentication and authorization. The purpose is to authenticate incoming users based on the NAS-PORT-ID. The problem is that we cannot find any solution for the Service Router (Alcatel 7750) to send the NAS-PORT-ID to act as USERNAME. The username field is set to the MAC address.

The ACS requires a USERNAME and there is not a way to manipulate the User-Name value once it is received.

We heard that it could be possible to use the freeradius to act as a proxy for the Cisco secure ACS.

This is what we want:

User -> [SR] -> User-Name = “MAC:xx.xx.xx.xx” Password = “secret” NAS-Port-Id = 1/1/4.1001.129 -> [FR] -> User-Name = “1/1/4.1001.129” Password = “secret” -> [ACS 5.3]

Is there a solution for this option in the Freeradius?

Is there a way to manipulate the User-Name sent from the service router, (MAC address), and change it to its NAS-Port-Id before it reaches the ACS RADIUS with help from the freeradius acting as a proxy?