Basic Operation
All communications regarding
RADIUS
accounting are done with an Accounting-Request
packet. A client that is participating in the RADIUS accounting
process will generate an Accounting Start packet,
which is a specific kind of Accounting-Request
packet. This packet includes information on which service has been
provisioned and on the user for which these services are provided.
This packet is sent to the RADIUS accounting server, which will then
acknowledge receipt of the data. When the client is finished with the
network services, it will send to the accounting server an
Accounting Stop packet (again, a specialized
Accounting-Request packet), which will include the
service delivered; usage statistics such as time elapsed, amount
transferred, average speed; and other details. The accounting server
acknowledges receipt of the stop packet, and all is well. If the
server does not or cannot handle the contents of the
Accounting-Request packet, it is not allowed to
send a receipt acknowledgment to the client.
In this instance, the RFC recommends that a client continue to send
its packets to the accounting server when it has not received an
acknowledgment that its Accounting-Request packet has been processed. In fact, in large distributed networks, it is desirable to have several accounting servers act in a round-robin fashion to handle failover and redundancy needs. An administrator can carry this mentality further and designate certain accounting servers to handle different ...