[Iccrg] Is ECN too complicated?

[Bob Briscoe]

Sorry, I didn't catch the name of the questioner in iCCRG just now...

I wanted to carry this question over to the list. It is central to 
challenge #1 in our open issues. What level of router support for cc 
is appropriate?

My premise is that ECN is the most minimal mechanism we can imagine 
on each queue, to get info out of those boxes to the edge of the 
network, where capacity sharing can be controlled - rather than 
trying to do capacity sharing on every resource (which I have shown 
is not even the right thing to be wanting to do).

So I was a bit surprised to hear ECN criticised as too complex. It's 
a tiny no. of cycles per packet. If ECN is too complex, whither RCP?

BTW, I've recently proved that the parts of the ECN algo that make 
marking follow a uniform distribution can be removed (redundant). 
Also, recent work by Damon Wischik iwhere there's hi stat mux (the 
boxes we're worried about) you don't even need the RED ramp, just a 
step at a small number of packets.

If ECN is still too complex, I'm at a loss (irony intended).



Bob



________________________________________________________________
Bob Briscoe,               Networks Research Centre, BT Research