Re: TCP Window Optiimization with LFN.

TAC is having me give this a whirl.

Global

ip tcp window-size 8625000

Config on L2 Interfaces

hold-queue 4096 in

hold-queue 4096 out

I calc-ed the estimated Window via this link.

http://bradhedlund.com/2008/12/19/how-to-calculate-tcp-throughput-for-long-distance-links/

It's amazing I get a good 30MB from a 3GB ISO off of a Server08 box. From
a Server 03, I'm lucky to get 85bytes on a 22MB file.

SE and AM are getting some WAAS and ASR quotes together. *Puts on nut cup*

Thanks guys,
JB

On Thu, Aug 16, 2012 at 3:27 PM, Joseph L. Brunner
<joe_at_affirmedsystems.com>wrote:

> We tried that extensively in windows 2003 and other things - never worked
> or made a difference....
>
>
>
> -----Original Message-----
> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
> Dan Shechter
> Sent: Thursday, August 16, 2012 4:12 PM
> To: JB Poplawski
> Cc: ccielab_at_groupstudy.com
> Subject: Re: TCP Window Optiimization with LFN.
>
> It depends on what you are looking for: High BW, Latency issues or both.
>
>
> For a large window size,
> http://en.wikipedia.org/wiki/TCP_window_scale_option should do it. As
> long as there are no CRC errors on the path, there is no much harm enabling
> it by default.
>
> For latency issues of chatty protocols, we will all have to wait for the
> results of CERN experiments to see if we can send packets faster then the
> speed of light... ;) . For some applications, WAAS "reducing" the latency
> is much more important than BW.
>
>
> HTH,
> Dan #13685 (RS/Sec/SP)
> The CCIE troubleshooting blog: http://dans-net.com Bring order to your
> Private VLAN network: http://marathon-networks.com
>
>
>
>
>
> On Thu, Aug 16, 2012 at 9:07 PM, JB Poplawski <jb.poplawski_at_gmail.com
> >wrote:
>
> > Good afternoon,
> >
> > My token question out to the group as I await TAC.
> >
> > I have a network with Gb links between sites. Connected like such:
> > Site A < 7ms > Site B < 71ms > Site C <9ms> Site D
> >
> > End to end latency between Site A and Site D is 69ms. My numbers
> > above are the average given from CLI.
> >
> > I've been reading on LFNs (Long Fat Networks) and basically I need to
> > optimize the TCP Window size (calculated to 8625KB).
> >
> > My question, where do I implement it?
> > Site A and Site D? Or Site B and Site C?
> >
> > If I implement on Site B and Site C, how does that impact Site C to
> > Site D, etc?
> >
> > Any ideas?
> >
> > We previously had MPLS connection with WAAS which optimized traffic.
> > Now since we're running Gb, we removed WAAS (our WAAS boxes were only
> > rated to 50Mbps).
> >
> > Any suggestions? Am I on the right path?
> >
> > Any help is greatly appreciated.
> > JB
> >
> >
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Received on Thu Aug 16 2012 - 15:37:18 ART