FreeRadius and Ericsonn NAS

Has anyone connected FreeRadius to an Ericsonn NAS which identifies itself as:- Ericsonn AB - Packet Core Networks My FreeRadius setup is receiving an Access-Request and is sending back an Access-Accept but the NAS thinks it is being rejected. Apparently this NAS does not have easily accessible diagnostic logs and matters are complicated as there is one guy with access to the Ericsonn who has only ever used Steel Belted Radius before, me who has never used FreeRadius (or any other Radius come to that) and a network managed by others who had firewall problems getting the packets to flow between the NAS and FreeRadius. Any help greatfully received, David