Volume Limit per user monthly

[Fajar A. Nugraha]

On Fri, May 4, 2012 at 2:15 PM, Johan Meiring <jmeiring at pcservices.co.za> wrote:
> On 2012/05/04 09:06 AM, Fajar A. Nugraha wrote:
>>
>>
>> First thing to ask your NAS vendor is whether they support the volume
>> equivalent of  session-timeout. For example, chillispot has
>> ChilliSpot-Max-Total-Octets. If it doesn't, then there's no way to
>> enforce the limit using any radius server. Period.
>
>
> Unless....
>
> You locally keep track of the Total usage in all sessions for the month.
> When you receive an accoungting update, you do the math.
>
> If the user is over, you send a POD.
>
> This is how our local telco works with ADSL.

Correct. That would be a good method if your NAS supports POD, and
you're willing to tolerate some excess traffic (since you only get
interim-update packets at certain time interval, not certain volume
interval).

>
> Unfortunately you only get Accounting Updates every hour,

That should be configurable through Acct-Interim-Interval attribute
sent by radius. However:
- some NAS limits the minimum allowed value (e.g. chillispot ignores
values less than 60)
- if you set it too low, the load your accting backend (e.g. db) might
get too high, as there will be more accounting packets to process.

5, 15, or 60 minutes is usually a good start for
Acct-Interim-Interval, depending on your current load.

-- 
Fajar