RADIUS

Name

Idle-Timeout

Synopsis

Attribute Number	28
Length	6
Value	ENUM
Allowed in	Access-Accept, Access-Challenge
Prohibited in	Access-Request, Access-Reject
Presence in Packet	Not required
Maximum Iterations	1

An administrator may configure the Idle-Timeout attribute so that the client gear or RADIUS server disconnects a session after a predetermined period of inactivity. The value in this attribute, four-octets long, is the maximum number of seconds a connection may remain active yet idle.

The Idle-Timeout attribute was a good idea for its time. Unfortunately, an administrator must be wary of many small software applications that exist today that are designed to defeat this mechanism. The software ranges in complexity from simple to—wait for it—complex. The lower end of the software simply pings a random server at steady intervals (usually every minute), while the upper end uses sophisticated algorithms to generate traffic more regular yet unpredictable than a ping.