TCP out-of-order packets.
brooks at one-eyed-alien.net
Wed Jan 12 21:48:16 PST 2005
On Wed, Jan 12, 2005 at 05:07:36PM -0800, Julian Elischer wrote:
> I have a link which is provided by someone else that is 7 x E1s aggregated.
> At leat it looks that way to me when I get to see it. however I have
> only been able to get
> 60kB.sec across this, despite having a tcp window size of 131072 bytes..
> After investigation it appears that the link is massively re-orderring
> groups of upto 10 packets may appear in random order. (Maybe more, bu tI
> have seen 10)
> in fact packets are rarely IN order.
> This plays havoc with the tcp sessions.
> I was thinking of writing a hacked up version of NATD that
> instead of doing NAT, just did a pre-sort on packets from each session,
> so that the receiver would
> see a stream of IN-order packets, with occasional delays.
> firstly, does anyone have any tools to do this already (why build when
> you can borrow)
> and secondly, does anyone have any experience with this sort of problem?
> I have no control over or access to the link.. all I have is a promise
> that they will deliver
> 14Mb/Sec. with approc 300mSec. RTT to me but there is no promise about
> packet order.
> I just get a 100Mb ethernet cable.
Have you tried Andre's TCP reassembly rewrite? He says he saw
significant improvements in the face of major reordering.
Any statement of the form "X is the one, true Y" is FALSE.
PGP fingerprint 655D 519C 26A7 82E7 2529 9BF0 5D8E 8BE9 F238 1AD4
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