Re: [Bloat] bufferbloat paper

[Mark Allman <mallman@icir.org>]

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> >> but if the connection from the laptop to the AP is 54M and the
> >> connection from the AP to the Internet is 1G, you are not going to
> >> have a lot of buffering taking place. You will have no buffering on
> >> the uplink side, and while you will have some buffering on the
> >> downlink side, 54M is your slowest connection and it takes a
> >> significantly large amount of data in flight to fill that for seconds.
> >
> > 54Mbps *might* be your slowest link.  It also could be somewhere before
> > incoming traffic gets anywhere close to any of the CCZ gear.  E.g., if
> > the traffic is from my DSL line the bottleneck will be < 1Mbps and on my
> > end of the connection.
> 
> Wait a min here, from everything prior to this it was sounding like
> you were in a fiber-to-the-home experimental area that had 1G all
> the way to the houses, no DSL involved.

You noted that in the downlink direction (i.e., traffic originating at
some arbitrary place in the network that is *outside* the FTTH network)
would be bottlenecked not by the 1Gbps fiber that runs to the house, but
rather by the final 54Mbps wireless hop.  All I am saying is that you
are only half right.  We know the bottleneck will not be the 1Gbps
fiber.  It *might* be the 54Mbps wireless.  Or, it *might* be some other
link at some other point in the Internet before the traffic reaches the
1Gbps fiber that connects the house.

My example is if I originated some traffic at my house (outside the FTTH
network) that was destined for some host on the FTTH network.  I can
pump traffic from my house at < 1Mbps.  So, that last hop of 54Mbps
cannot be the bottleneck.

allman




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