nanog mailing list archives
RE: Jumbo Frames (was Re: MAE-EAST Moving? from Tysons corner torestonVA. )
From: "Roeland Meyer (E-mail)" <rmeyer () mhsc com>
Date: Mon, 19 Jun 2000 15:53:15 -0700
Marc Slemko: Monday, June 19, 2000 10:06 AM On Mon, 19 Jun 2000, Roeland M.J. Meyer wrote:I should have re-caveated, for your benefit. I am not testing with a bazillion-byte file. I am testing with query/response against a RDBMS host. IOW, a typically real-world(tm)
practical
application. The responses range from 3-50KB, with anomalies
out
to 100KB. The slow-start algorithm has been identified as theErm... no, then your problem is opening and closing TCP connections all the time. Don't do that.
I don't have much choice there. Each query/response is a new connection. Even SQLnet is limited with batch query optimization.
It hurts you in a lot of other ways.
Yes, it does. I'm still scraping off the charred back-side meat.
It really isn't appropriate to go around saying "you need larger MTUs to fill a 100 meg link, period" when you really mean "in one
particular
situation where I am opening and closing TCP connections and only sending a very small amount of data over each, you need larger MTUs".
Hm, I don't remember the "period" and I thought that I'd outlined my case a few messages back.
I wouldn't be so quick to say slow start is useless, either. Perhaps with small window sizes, but as soon as they get big enough...
Here is where you may not have thought it through enough. On a dedicated FDX link, what need is there for slow-start? Only the transmitter and receiver are on the wire and the other-end has a separate transmit circuit to talk back with (the other side of the FDX link). If the switch can't keep up then I need a switch that can. In this case, I happen to know that the switch is fine. I'm feeding CAT5 straight from the switch to the NIC on the server. The other side is similarly connected. Slow-start is a legacy requirement for non-switched networks and is still exists for legacy reasons. In switched FDX environments, it would be real nice if I could just turn it off, as a configuration issue. In fact, there's a lot of stuff that could probably be stripped from a stack, for switched FDX environs and modern SMP hosts. Even switched 100baseTX could benefit.
Current thread:
- Re: Jumbo Frames (was Re: MAE-EAST Moving? from Tysons corner to reston VA. ) Vadim Antonov (Jun 19)
- <Possible follow-ups>
- Re: Jumbo Frames (was Re: MAE-EAST Moving? from Tysons corner to reston VA. ) Richard A. Steenbergen (Jun 19)
- RE: Jumbo Frames (was Re: MAE-EAST Moving? from Tysons corner toreston VA. ) Roeland Meyer (E-mail) (Jun 19)
- RE: Jumbo Frames (was Re: MAE-EAST Moving? from Tysons corner toreston VA. ) sthaug (Jun 19)
- RE: Jumbo Frames (was Re: MAE-EAST Moving? from Tysons corner toreston VA. ) Roeland M.J. Meyer (Jun 19)
- RE: Jumbo Frames (was Re: MAE-EAST Moving? from Tysons corner toreston VA. ) Marc Slemko (Jun 19)
- RE: Jumbo Frames (was Re: MAE-EAST Moving? from Tysons corner torestonVA. ) Roeland Meyer (E-mail) (Jun 19)
- RE: Jumbo Frames (was Re: MAE-EAST Moving? from Tysons corner toreston VA. ) Roeland Meyer (E-mail) (Jun 19)
- Re: Jumbo Frames (was Re: MAE-EAST Moving? from Tysons corner toreston VA. ) Bennett Todd (Jun 19)
- Re: Jumbo Frames (was Re: MAE-EAST Moving? from Tysons corner toreston VA. ) Stephen Sprunk (Jun 19)