Subject: [AAA-WG]: Accounting question

From: "Guillermo Guardia-Lozano (ECE)" <[email-masked]>
Date: Fri, 27 Jul 2001 16:52:03 +0200

Hello,
 One single question related to accounting that maybe someone can answer.

When a client uses both authentication and accounting services, there are two flows of messages
related to the same Session-Id one for authentication/authorization  (AuthenReq->answer->ReAuthenReq->answer....STR->STA) and other for accounting (ACR-start->ACA->ACR-Interim->ACA->...->ACR-Stop->ACA)
The question is:
from the point of view of the Home Server these flows can be considered independant
or on the contrary accounting flow must be always tied to the authen/author
flow ?

 Is it a MUST for the Diameter client, to sent all the accounting messages related to a session  (and wait for the successful answer
from the Diameter server), before sending the Session Termination Request message   ? 
 
 A sequence like the following one must be always expected ?,     ..  OR  ...  for instance one like this could be also possible ?

       client                        Home Server    client                         Home Server
         |                                |            |                                |
         |    Authen/Autho REQUEST        |            |    Authen/Autho REQUEST        |
         |------------------------------->|            |------------------------------->|
         |        ANSWER                  |            |        ANSWER                  |
         |<-------------------------------|            |<-------------------------------|

         |          ACR  START            |            |          ACR  START            |
         |------------------------------->|            |------------------------------->|
         |          ACA                   |            |          ACA                   | 
                  .. interims ..                               .. interims ..

         |          ACR   STOP            |            |          STR                   |
         |------------------------------->|            |------------------------------->|
         |          ACA                   |            |          STA                   |
         |<-------------------------------|            |<-------------------------------|

         |          STR                   |            |          ACR   STOP            |
         |------------------------------->|            |------------------------------->|
         |          STA                   |            |          ACA                   |
         |<-------------------------------|            |<-------------------------------|
         |                                |            |                                |

Thanks

---

From: Pat Calhoun <[email-masked]>
Date: Fri, 27 Jul 2001 08:27:47 -0700

> or on the contrary accounting flow must be always tied to the authen/author

Accounting can be done without any authentication and/or authorization.
There is a state machine for accounting only applications.

> from the Diameter server), before sending the Session Termination Request message   ? 

It would be a REALLY good idea, but I am not sure that we can enforce that :(

>          |    Authen/Autho REQUEST        |            |    Authen/Autho REQUEST        |

That would be my preferred approach, but again, it isn't mandatory.

PatC