Identify amount of traffic to special IP address in Radius

Christian Kuhtz kuhtzch at corp.earthlink.net
Wed Mar 1 05:28:14 UTC 2006


On Feb 28, 2006, at 11:59 PM, Joe Shen wrote:

>> why in the world
>> would you want to do something like that rather than
>> have another
>> device generate flow records which you then can
>> correlate with RADIUS
>> accounting data?
>>
>
> The reason is the cost of system building. As there
> are a lot of broadband subscribers, if we want to
> corelate subscriber with web site they visit we have
> to make Radius allocate a fixed IP to a special
> subscriber. Netflow based accounting is costy and we
> could not guarantee its accuracy.

I would submit to you that getting such functionality built and  
operating via RADIUS is expensive as well.  If you have a lot of  
broadband subscribers, your BRAS will already be busy doing what it  
does 'best': terminating subscriber sessions.  Plus, you have to get  
your vendor to implement such a feature.. I haven't seen something  
like what you describe in the years of looking at BRAS requirements.   
But, that doesn't mean it doesn't exist in a scalable fashion.

> In fact, we only need to identify a small set of IPs
> which should not be considered in accounting.

If you need to generate IP accounting for just a small set of IPs,  
the above engineering challenge you describe is very straightforward  
for capturing flow records.

YMMV, of course. ;-)




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