[e2e] Stupid Question: Why are missing ACKs not considered as indicator for congestion?

Lachlan Andrew lachlan.andrew at gmail.com
Wed Jan 31 16:34:51 PST 2007

Greetings Lloyd,

On 31/01/07, Lloyd Wood <L.Wood at surrey.ac.uk> wrote:
> It's possible for the sender to infer that an ack has been lost, based on subsequent receiver behaviour in sending a cumulative ack including packets received that the sender didn't get individual acks for.

No, that was my point.  We can't distinguish between ACKs which are
lost and those which are never sent in the first place.

Also, having a unique identifier (like a timestamp) isn't the same as
having sequence numbers which can say "We're (not) consecutive".  The
latter can detect loss but the former can't.


Lachlan Andrew  Dept of Computer Science, Caltech
1200 E California Blvd, Mail Code 256-80, Pasadena CA 91125, USA
Phone: +1 (626) 395-8820    Fax: +1 (626) 568-3603

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