RE: question on algorithm for radius based accouting

["Alex Rubenstein" <alex () corp nac net>]

>   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
suggest.


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

Yes.


>    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.