Name

Called-Station-ID

Synopsis

Attribute Number

30

Length

3 or more octets

Value

STRING

Allowed in

Access-Request

Prohibited in

Access-Accept, Access-Reject, Access-Challenge

Presence in Packet

Not required

Maximum Iterations

1

The value in this packet can tell the NAS gear what number the user dialed to gain access to its service. Using the Dialed Number Identification Service (DNIS), the NAS gear may use this data to authenticate based on location (if each point of presence in various locations has a different number). Also, the Called-Station-ID can be used to identify which RADIUS proxy server forwarded the request. Using this attribute in that manner is called “numbered-realm proxying.”

Outside of standard dial-up Internet access, the Called-Station-ID attribute can be used in other applications. For example, in the publicly available wireless access industry, typically you will find the MAC address of the access point to which the wireless card is connected in this field, with the octets separated by hyphens. While this is certainly not a prescribed standard by any RFC, this is a best practice.

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