[R-C] Charter -> congestion avoidance vs. congestion control?

[Harald Alvestrand]

On 08/06/2012 02:47 PM, Mirja Kuehlewind wrote:
> Hi,
>
> one more comment regarding the charter. I was wondering if there is a
> difference between congestion avoidance and congestion control. I would say
> congestion avoidance is the more general term, while congestion control
> implies some kind of control loop.
When I first learned networking ~30 years ago, "congestion avoidance" 
was the term used when you managed things so that congestion at the 
media level could never happen (token ring, ATM), while "congestion 
control" was the whole area of what you did either to avoid congestion 
or to deal with it once it happened.

So I'd prefer "congestion control", since congestion is a fact of life; 
we're dealing with it, not avoiding it at all cost - but I'm a bit 
old-fashioned.

               Harald




>
> In case of real-time media traffic, as we have specific traffic
> characteristics, we might end up with something that e.g. only switches
> between certain pre-defined rate depending on feedback that we maybe get
> (only) once per RTT. This is quite different form current (TCP) congestion
> control where you calculate the sending rate based on continuous feedback
> (assuming you have more or less all the time data to send). Would we consider
> both as congestion control or only the latter case which is TCP-like
> congestion control?
>
> I would propose to only talk about congestion avoidance in the charter to make
> sure that we not only aim for TCP-like congestion control but also a solution
> as described above would be in the charter.
>
> Mirja
>
>
> On Thursday 02 August 2012 19:12:30 Michael Welzl wrote:
>> Hi all,
>>
>> There were two minimal changes to the charter, which is at:
>> https://sites.google.com/a/alvestrand.com/rtp-congestion/bof-planning-page/
>> wg-charter---input-to-vancouver
>>
>> It now explicitly says that the following are out of scope:
>> * Active queue management; modifications to TCP of any kind; and
>> * Multicast congestion control (common control of multiple unicast
>> flows is in scope).
>>
>> Other than that, the charter hasn't changed since the last version
>> that was sent around in May.
>>
>> Cheers,
>> Michael
>>
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>> Rtp-congestion at alvestrand.no
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>
>