[Cake] active sensing queue management

Daniel Havey dhavey at gmail.com
Fri Jun 12 10:44:20 EDT 2015

On Thu, Jun 11, 2015 at 6:49 PM, David Lang <david at lang.hm> wrote:
> On Wed, 10 Jun 2015, Daniel Havey wrote:
>> We know that (see Kathy and Van's paper) that AQM algorithms only work
>> when they are placed at the slowest queue.  However, the AQM is placed
>> at the queue that is capable of providing 8 Mbps and this is not the
>> slowest queue.  The AQM algorithm will not work in these conditions.
> so the answer is that you don't deploy the AQM algorithm only at the
> perimeter, you deploy it much more widely.
> Eventually you get to core devices that have multiple routes they can use to
> get to a destination. Those devices should notice that one route is getting
> congested and start sending the packets through alternate paths.
> Now, if the problem is that the aggregate of inbound packets to your
> downstreams where you are the only path becomes higher than the available
> downstream bandwidth, you need to be running an AQM to handle things.
> David Lang

Hmmmm, that is interesting.  There might be a problem with processing
power at the core though.  It could be difficult to manage all of
those packets flying through the core routers.

David does bring up an interesting point though.  The ASQM algorithm
was originally designed to solve the "Uncooperative ISP" problem.  I
coined the phrase, but, you can fill in your own adjective to fit your
personal favorite ISP :^)

The paper doesn't indicate this because I got roasted by a bunch of
reviewers for it, but, why not use an ASQM like algorithm other places
than the edge.  Suppose you are netflix and your ISP is shaping your
packets?  You cant do anything about the bandwidth reduction, but, you
can at least reduce the queuing...Just food for thought. :^)

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