DPI or Flow Management
Howard C. Berkowitz
hcb at netcases.net
Sun Mar 1 17:52:05 UTC 2009
> -----Original Message-----
> From: Francois Menard [mailto:francois at menards.ca]
> Sent: Sunday, March 01, 2009 11:49 AM
> To: Lorell Hathcock
> Cc: 'nanog list'
> Subject: Re: DPI or Flow Management
> Its like the post office getting envolopes by the truckload, then
> opening each envelope, read the content, to decide when to send the
> opened letter for delivery, either by foot or car, claiming that such
> a decision process will prevent envelopes from flooding the post
> office, coming into the post office for delivery in the last mile.
> On the other hand, traffic management such as flow management, deal
> with stuff differently by ensuring that the envelopes do not get to
> the post office too fast, thus permitting the letters be dispatched
> always by car, except those envelopes which are arriving to the post
> office, exhibiting behaviour of P2P, which are then sent for delivery
> by foot. In this latter case, the envelopes are never opened.
There is, however, at least one more dimension with postal or package
delivery services. They offer different delivery priorities with different
pricing, may have surcharges or refuse large content that the physical
transport technically could carry, and offer sender-pays and receiver-pays
A few specialized cases do apply as well, such as some package delivery
services accepting and handling hazardous materials only with declaration
It seems that this discussion emphasizes technical capabilities, which
certainly are relevant, but does not necessarily consider economic
incentives or disincentives. We are probably in agreement that either DPI or
traffic analysis could identify high-volume P2P; how does one deal with the
customer assumption that they "should" be able to do whatever they like?
Content distribution networks and caches do allow a much cleaner economic
model, if not as convenient.
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