Re: [e2e] host-level aggregated congestion control citations

On Aug 31, 2007, at 6:23 PM, Jitu Padhye wrote:

> One candidate is the congestion manager idea proposed by Hari
> Balakrishnan and his students at MIT.
>
> http://nms.lcs.mit.edu/cm/
>
> I don't know whether there are any commercial systems/products that
> use the idea.

Not to my knowledge. Hari and Srini wrote an RFC for it, as Joe noted (RFC 2134); we implemented it in Linux 2.2 and the source code remains freely available, but to my knowledge, that's about the last development that occurred on it. The hooks that we tied into in Linux have changed significantly since then.

Linux's latest round of TCP-ness has a more modular framework that allows congestion control algorithms to be exchanged for each other in the kernel - this doesn't achieve the sharing benefits from the CM or the ability to have congestion-controlled UDP flows, but it gets some of the modularity benefits of the CM.

Bryan Ford's paper at SIGCOMM this year on Structured Stream Transport (http://pdos.csail.mit.edu/uia/sst/) offers a "sub-stream" abstraction that permits congestion sharing between multiple flows, but I get the impression that it's intended mostly to do so between flows from the same application, and the current implementation is a per-application user-space library.

If you have any questions about the CM, we'd be happy to answer them, and even happier to see someone interested in pushing on it further. It's been a couple years, but we can dust off our brains...

   -Dave

>
> - Jitu
>
> -----Original Message-----
> From: end2end-interest-bounces@postel.org [mailto:end2end-interest-
> bounces@postel.org] On Behalf Of Dave Crocker
> Sent: Friday, August 31, 2007 2:37 PM
> To: end2end-interest@postel.org
> Subject: [e2e] host-level aggregated congestion control citations
>
> Folks,
>
> I am looking for a couple of citations, if there are any.
>
> Once upon a time, TCP did congestion control strictly on a per-
> connection
> behavior. I seem to recall that there was later work on aggregating
> congestion information, to get better behavior across concurrent
> connections
> between the same host-pair.
>
> If this is in current use, I'd like to review the mechanism(s).
>
> Yes?
>
> Thanks.
>
> d/
> --
>
> Dave Crocker
> Brandenburg InternetWorking
> bbiw.net
>
>

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