question on algorithm for radius based accouting

Alex Rubenstein alex at
Fri Aug 17 03:52:34 UTC 2007

>   My question is:  what's the best algorithm for
> constrcting  broadband access record from radius
> accouting packets?

Read the RFC. No, I am being serious.

>    Record Accouting-on packet arriving time ->
>     record Accouting-Off packet's Acct-Session-Time
> and Acct-Delay-Time  ->
>     The Log-off time is calculated as:
>        Accouting-on time + ( Acct-Session-Time -
> Acct_delay-Time)

Or, take the acct record from logoff, and:

	(time stop acct record rec'd) - (acct-delay-time)

Either will work. However, it's somewhat more common to do what I

>       Log-on time is calculated as:
> Accouting-off arriving time - ( Acct-Session-Time -
> Acct_delay-Time)


>    Are the two methods have the same effect on
> calculating result?  If radius packets were sent to
> two accouting systems simulataneusly, while the two
> system takes the different algorithm, will there be
> any difference between the result of accouting ?

They should yield (approximately) the same result. But, to be pedantic,
you haven't accounted for latency within the network.

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