RADIUS

Name

Login-LAT-Group

Synopsis

Attribute Number	36
Length	34
Value	STRING
Allowed in	Access-Request, Access-Accept
Prohibited in	Access-Reject, Access-Challenge
Presence in Packet	Not required
Maximum Iterations	1

The LAT protocol uses a form of authentication based on a bit pattern known as the “group code,” and this RADIUS attribute allows the group code to be carried inside Access-Request and Access-Accept packets. Much like other attributes that can be found inside both the Request and Accept packets, its presence inside the Request packet is simply a hint, while its presence in the Accept packet is definite.

If this attribute is present, then the Login-Service attribute must also be present.

RADIUS and Local Area Transport

These attributes are specific to RADIUS’s support of the Local Area Transport (LAT) protocol, originally developed by Digital Equipment for use of networks consisting of VAX equipment. LAT is unique because it allows the client to create a virtual terminal connection by using asynchronous connections across some type of LAN.

LAT has some specific characters and operators that it recognizes inside a packet, so the RADIUS RFC has created a special string data type called LAT STRING, which distinguishes some characters, $, -, ., _, and most of the characters in the ISO Latin-1 set. Further, these strings must be case sensitive.