nanog mailing list archives
[no subject]
From: Jim Shankland <nanog () shankland org>
Date: Tue, 27 Mar 2007 15:32:34 -0700
<michael.dillon () bt com> writes:
Use GigE cards on the servers with a jumbo MTU and only buy IP network access from a service provider who supports jumbo MTUs end-to-end through their network.
I'm not sure that I see how jumbo frames help (very much). The principal issue here is the relatively large bandwidth-delay product, right? So you need large TCP send buffers on the sending side, a large (scaled) receive window on the receiver side, and turn on selective acknowledgement (so that you don't have to resend the whole send buffer if a packet gets dropped). At 45 Mb/s and 120 ms RTT, you need to be able to have ca. 700 KBytes of data "in flight"; round up and call it a megabyte. Having said that, I too have tried to configure Windows to use a large send buffer, and failed. (In my case, it was Windows machines at a remote location sending to Linux machines.) I'm not a Windows person; maybe I didn't try hard enough. In the event, I threw up my hands and installed a Linux proxy server at the remote site, appropriately configured, and went home happy. Jim Shankland
Current thread:
- TCP and WAN issue Philip Lavine (Mar 27)
- Re: TCP and WAN issue Joe Abley (Mar 27)
- Re: TCP and WAN issue Joe Abley (Mar 27)
- Re: TCP and WAN issue Roland Dobbins (Mar 27)
- Re: TCP and WAN issue Robert Boyle (Mar 27)
- Re: TCP and WAN issue JAKO Andras (Mar 27)
- RE: TCP and WAN issue michael.dillon (Mar 27)
- [no subject] Jim Shankland (Mar 27)
- RE: Jumbo frames michael.dillon (Mar 27)
- RE: Jumbo frames Jim Shankland (Mar 27)
- Re: Jumbo frames Andy Davidson (Mar 29)
- RE: Jumbo frames michael.dillon (Mar 29)
- Re: Jumbo frames Stephen Sprunk (Mar 30)
- [no subject] Jim Shankland (Mar 27)
- RE: Jumbo frames Hank Nussbacher (Mar 27)
- Re: TCP and WAN issue Joe Abley (Mar 27)
- Re: Perry Lorier (Mar 27)
- Re: TCP and WAN issue Steve Meuse (Mar 27)