Hi, I don’t know what your scale is but setting a 15minute interim radius update has always worked well for me. A standard freeradius server running on SSD’s would be able to handle the load from 100k users without too much of a load issue. Above that load balancing radius requests among servers is not really that difficult.  

From: NANOG <nanog-bounces@nanog.org> On Behalf Of aun Joe
Sent: Thursday, 24 January 2019 9:28 PM
To: NANOG <nanog@nanog.org>
Subject: Any way to collect network usage data for dial-up subscriber

NANOGers ,

     is there anyway for AAA to get special  online subscriber usage information without enable interim accouting on BRAS?

    Reading through RADIUS protocol , it seems that if we want to get online subscriber information enable interim accounting on BRAS is the only way .

     But, if enable that on BRAS ,, all online subscribers accouting infromation will be reported periodically.  that will generate too much load on AAA , and 

    we  need to monitor a small set of subscribers  only.

  thanks in advance.

joe sun