[nsp] Rate - limiting

[Mikael Abrahamsson]

On Thu, 20 May 2004 james at thehamptonfamily.us wrote:

> Which would rate limit them to 512K!?

Rate limiting works well for many TCP sessions, mostly in the 30-50 
megabit/s or higher speed range.

Rate limiting at lower speeds severelt impacts TCP performance, a single 
TCP session hitting a rate limit will start, hit the ratelimit, lose 
several packets, pretty much go into slow-start, go logarithmically up 
again to the rate limit, hit the hard ceiling and then go into slow-start 
again, cutting the used bandwidth to approx 40% of the ratelimit.

As stated before, shaping is what you want to do preferrably, but shaping 
means memory and that is more expensive.

-- 
Mikael Abrahamsson    email: swmike at swm.pp.se