Thread (29 messages) flat view 29 messages, 7 authors, 2007-02-13

Re: [patch 3/3] tcp: remove experimental variants from default list

From: Stephen Hemminger <hidden>
Date: 2007-02-13 20:23:26

My somewhat biased capsule summary is:

Algorithms:

Reno: Linux never really implemented pure Reno anyway, see
	http://www.cs.helsinki.fi/research/iwtcp/papers/linuxtcp.pdf
   This makes anybody doing pure ns2 based comparisons suspect.
   The problem is Reno rolls off

HSTCP: too aggressive and can be unfair
BIC: not fair to Reno
CUBIC: good fairness but depends on additional traffic to converge faster
HTCP: good fairness but high variation
Vegas: reduces loss but sensitive to delay variation and back channel
Westwood: reduces loss but slow growth on high BDP

Not evaluated enough: Hydra, VENO

The biggest issue with CUBIC (and before that BIC) has been 
bugs with a long mean-time-to-discovery (but MTTR has been fast). 
The others don't seem to get as much attention, perhaps
we should turn a different congestion control algorithm as default
on each -mm release to get people to actually look at the others.

There are some newer congestion control algorithms coming:
TCP Illinois, a newer version of Westwood, TCP-Fusion, Exp-TCP
and maybe Adaptive RENO. Stay tuned.

-- 
Stephen Hemminger [off-list ref]
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help