* the congestion window rfc2001
@ 2013-08-13 23:35 Dong Fang
2013-08-13 14:29 ` Yuchung Cheng
2013-08-13 23:58 ` Dong Fang
0 siblings, 2 replies; 3+ messages in thread
From: Dong Fang @ 2013-08-13 23:35 UTC (permalink / raw)
To: netdev
hi, all
http://tools.ietf.org/html/rfc2001
1. When the third duplicate ACK in a row is received, set ssthresh
to one-half the current congestion window, cwnd, but no less
than two segments. Retransmit the missing segment. Set cwnd =
ssthresh + 3 times the segment size. This inflates the
-- what is the meaning of '3'
congestion window by the number of segments that have left the
network and which the other end has cached (3).
2. Each time another duplicate ACK arrives, increment cwnd by the
segment size. This inflates the congestion window for the
additional segment that has left the network.
-- why do this
Transmit a packet, if allowed by the new value of cwnd.
3. When the next ACK arrives that acknowledges new data, set cwnd
to ssthresh (the value set in step 1). This ACK should be the
acknowledgment of the retransmission from step 1, one round-trip
time after the retransmission. Additionally, this ACK should
acknowledge all the intermediate segments sent between the lost
packet and the receipt of the first duplicate ACK. This step is
congestion avoidance, since TCP is down to one-half the rate it
was at when the packet was lost.
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: the congestion window rfc2001
2013-08-13 23:35 the congestion window rfc2001 Dong Fang
@ 2013-08-13 14:29 ` Yuchung Cheng
2013-08-13 23:58 ` Dong Fang
1 sibling, 0 replies; 3+ messages in thread
From: Yuchung Cheng @ 2013-08-13 14:29 UTC (permalink / raw)
To: Dong Fang; +Cc: netdev
Please ask those questions on more relevant list such as
tcpm@ietf.org. This list is for discussing Linux kernel networking
development, not generic TCP protocol.
On Tue, Aug 13, 2013 at 4:35 PM, Dong Fang <yp.fangdong@gmail.com> wrote:
> hi, all
>
>
> http://tools.ietf.org/html/rfc2001
>
>
> 1. When the third duplicate ACK in a row is received, set ssthresh
> to one-half the current congestion window, cwnd, but no less
> than two segments. Retransmit the missing segment. Set cwnd =
> ssthresh + 3 times the segment size. This inflates the
> -- what is the meaning of '3'
>
> congestion window by the number of segments that have left the
> network and which the other end has cached (3).
>
> 2. Each time another duplicate ACK arrives, increment cwnd by the
> segment size. This inflates the congestion window for the
> additional segment that has left the network.
> -- why do this
>
> Transmit a packet, if allowed by the new value of cwnd.
>
> 3. When the next ACK arrives that acknowledges new data, set cwnd
> to ssthresh (the value set in step 1). This ACK should be the
> acknowledgment of the retransmission from step 1, one round-trip
> time after the retransmission. Additionally, this ACK should
> acknowledge all the intermediate segments sent between the lost
> packet and the receipt of the first duplicate ACK. This step is
> congestion avoidance, since TCP is down to one-half the rate it
> was at when the packet was lost.
> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 3+ messages in thread
* the congestion window rfc2001
2013-08-13 23:35 the congestion window rfc2001 Dong Fang
2013-08-13 14:29 ` Yuchung Cheng
@ 2013-08-13 23:58 ` Dong Fang
1 sibling, 0 replies; 3+ messages in thread
From: Dong Fang @ 2013-08-13 23:58 UTC (permalink / raw)
To: netdev, Dong Fang
-------- Original Message --------
Subject: the congestion window rfc2001
Date: Tue, 13 Aug 2013 19:35:09 -0400
From: Dong Fang <yp.fangdong@gmail.com>
To: netdev@vger.kernel.org
hi, all
http://tools.ietf.org/html/rfc2001
1. When the third duplicate ACK in a row is received, set ssthresh
to one-half the current congestion window, cwnd, but no less
than two segments. Retransmit the missing segment. Set cwnd =
ssthresh + 3 times the segment size. This inflates the
-- what is the meaning of '3'
congestion window by the number of segments that have left the
network and which the other end has cached (3).
2. Each time another duplicate ACK arrives, increment cwnd by the
segment size. This inflates the congestion window for the
additional segment that has left the network.
-- why do this
Transmit a packet, if allowed by the new value of cwnd.
3. When the next ACK arrives that acknowledges new data, set cwnd
to ssthresh (the value set in step 1). This ACK should be the
acknowledgment of the retransmission from step 1, one round-trip
time after the retransmission. Additionally, this ACK should
acknowledge all the intermediate segments sent between the lost
packet and the receipt of the first duplicate ACK. This step is
congestion avoidance, since TCP is down to one-half the rate it
was at when the packet was lost.
^ permalink raw reply [flat|nested] 3+ messages in thread
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