[c-nsp] PPPoE Mid-session Shaping/Policing

[Michael Bowe]

> Date: Wed, 7 Jan 2009 14:49:18 +1100
> From: "Patrick Wu" <pwu828 at gmail.com>

> I have a L2TP/PPPoE setup in a 7206VXR and is working fine. What I now 
> want
> to do is to implement dynamic shaping/policing on the PPPoE services. ie, 
> I
> would like to shape/police a PPPoE service without disconnecting the
> session.
>
> I believe this can be implemented using RADIUS attributes? But not sure 
> how
> it is done exactly if it is possible at all. I'm already using RADIUS
> attributes to shape/police PPPoE sessions when they login initially, I now
> need to change the shaper/policer rate mid-session without disconnecting.

On our systems we need to slow the user to 64/64 once they have exceeded 
their monthly download limit. We have separate peak and off-peak time 
periods so you sometimes need to toggle the user's speed a couple of times 
per day. Kicking the session to apply the new limit is no good, that makes 
for unhappy customers.

It look a lot of reading, but in the end I got a working solution based on :
  * 12.2SB IOS
  * ISG
  ( 
http://www.cisco.com/en/US/docs/ios/12_2sb/isg/configuration/guide/isg_c.html )
  * RADIUS CoA
  ( http://www.cisco.com/en/US/docs/ios/12_2sb/isg/coa/guide/isgcoa3.html )

Be warned the ISG doco is pretty painful. It took me a long time to get a 
good understanding of how all the pieces fit into the puzzle. Once it was up 
and running though, its been working very well.

Michael.