Interoperability

The other side of any open standard is that it doesn’t always guarantee interoperability with other vendors’ implementations’. RADIUS’s implementations between different vendors can vary because the RADIUS standard specifically allows vendors to offer custom features or attributes in what are called AV pairs. If a vendor device doesn’t recognize the AV pair, it ignores it. To demonstrate the variations, the IETF implementation supports attributes, while Ascend supports 254. Cisco currently supports 58 attributes on Cisco Secure ACS, access servers, Ethernet switches, PIX firewalls, and VPN 3000 concentrators.