https://www.usenix.org/system/files/conference/atc14/atc14-paper-salameh.pdf

The paper I mentioned.
Usenix ATC'14 not NSDI.




On Sunday, 3 July 2016, Jonathan Morton <chromatix99@gmail.com> wrote:

>
> > On 3 Jul, 2016, at 10:06, David Lang <david@lang.hm <javascript:;>>
> wrote:
> >
> > do they delay the L2 Ack until the L4 ack comes back? If so, how does
> that work on long-latency connections where it takes a long time for the L4
> ack to show up?
>
> I’m pretty sure it’s only meant to work when the TCP endpoint is local to
> the receiving station, assuring low turnaround latency.  This is the
> typical case, so it’s a win.
>
> With that said, there’s no fundamental reason why the piggybacked L4 ack
> need be the one corresponding to the L2 ack.  It just needs to be a small
> packet that won’t unduly extend the airtime occupied by the ack anyway, and
> which won’t mind being lost if the L2 ack gets squashed.  A scheme allowing
> a certain amount of slop in this way would accommodate remote TCP endpoints
> as well as local ones.
>
>  - Jonathan Morton
>
>