[Iccrg] Is ECN too complicated?

[Mikael Abrahamsson]

On Fri, 31 Jul 2009, John Leslie wrote:

> We do need them to leave ECN marking alone. (Has someone documented
> which core router do and don't?)

I don't know of any core router that will zero the ECN marking, all I have 
seen either have ECN support (used in their WRED schemes) or they don't 
know anything about ECN and just ignores the bits and just passes the 
packet unchanged (ECN-wise).

>   I don't feel the need for more detail of why intelligence in core 
> routers is expensive. What we do need is an upper bound on packet drop 
> (without ECN marking coming first) in actual core routers.

>From what I have seen in recent major vendors, the new platforms seem to 
have around 50-200ms of buffers, coming down from the common 600ms 5+ 
years back.

This is for 10G and 40G interfaces.

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