Re: [PATCH] RFC2988bis + taking RTT sample from 3WHS for the passive open side

On Wed, Jun 8, 2011 at 4:39 PM, Eric Dumazet [off-list ref] wrote:

Le mercredi 08 juin 2011 à 15:26 -0700, Jerry Chu a écrit :

quoted

Eric,

It just occurred to me now that initRTO is being reduced, both TCP_SYN_RETRIES
and TCP_SYNACK_RETRIES should be bumped up a bit, to e.g., 7 (?) to meet the
3 minutes R2 requirement per RFC1122.

If you agree, I will submit another patch.

Good catch, but no RFC lowered yet this 3 minutes requirement ?

Not that I know of. BTW, I'm not as nearly concerned about RFC compliance
as what's the "right thing" to do, e.g., if apps have some expectation on
how long, e.g., a connect() call will persistent before ETIMEOUT...

With exponential backoff, initRTO of 3secs and 5 retries will last 189 secs
before ETIMEOUT. Setting initRTO to 1sec reduces this time to 63 secs.
Guess it's still more than one minute so it's not too bad. Now I don't think
it's a good idea to raise retries to 7 or 247 secs, which seems too long (more
than 4 minutes) just to be RFC compliant. Raising retries to 6 or allowing
127 secs might be more reasonable though.

Thought?

Jerry