* Shaping TCP ACK packets [not found] <b7c7ae97-0030-4397-a1e3-ec29babdff4d@jasiiieee> @ 2011-12-06 4:18 ` John A. Sullivan III 2011-12-06 5:59 ` Eric Dumazet 0 siblings, 1 reply; 2+ messages in thread From: John A. Sullivan III @ 2011-12-06 4:18 UTC (permalink / raw) To: netdev Hello, all. I've seen several sites recommend prioritizing TCP ACK packets using tc. Is that a good idea? I have two reservations: 1) If my line is congested, isn't delaying ACKs a good way to slow down the conversation? Accelerating ACKs under congestion sounds a bit like stuffing more food in my mouth when I'm already choking. 2) By messing with normal coordination of TCP, do I risk making a mess. Specifically, can I create problems with out of order packet delivery - send an ACK before the packet which should have preceded it? I suppose in a well behaved protocol that wouldn't happen but I'm not sure. Thanks - John ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: Shaping TCP ACK packets 2011-12-06 4:18 ` Shaping TCP ACK packets John A. Sullivan III @ 2011-12-06 5:59 ` Eric Dumazet 0 siblings, 0 replies; 2+ messages in thread From: Eric Dumazet @ 2011-12-06 5:59 UTC (permalink / raw) To: John A. Sullivan III; +Cc: netdev Le lundi 05 décembre 2011 à 23:18 -0500, John A. Sullivan III a écrit : > Hello, all. I've seen several sites recommend prioritizing TCP ACK > packets using tc. Is that a good idea? I have two reservations: > > 1) If my line is congested, isn't delaying ACKs a good way to slow > down the conversation? Accelerating ACKs under congestion sounds a bit > like stuffing more food in my mouth when I'm already choking. > It depends which way is congested. Sites recommends prioritizing ACKS on the up way, because most of the time ADSL links are assymetric. an uplink is congested. > 2) By messing with normal coordination of TCP, do I risk making a > mess. Specifically, can I create problems with out of order packet > delivery - send an ACK before the packet which should have preceded > it? I suppose in a well behaved protocol that wouldn't happen but I'm > not sure. Thanks - John > -- Well, if you prioritize true acks (packets with no payload), there is no reorder problem per se. ^ permalink raw reply [flat|nested] 2+ messages in thread
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2011-12-06 4:18 ` Shaping TCP ACK packets John A. Sullivan III
2011-12-06 5:59 ` Eric Dumazet
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