ISPs slowing P2P traffic...

Joe Greco jgreco at ns.sol.net
Sun Jan 13 18:58:30 UTC 2008


> Joe Greco wrote,
> > There are lots of things that could heavily stress your upload channel.
> > Things I've seen would include:
> >
> > 1) Sending a bunch of full-size pictures to all your friends and family,
> >    which might not seem too bad until it's a gig worth of 8-megapixel 
> >    photos and 30 recipients, and you send to each recipient separately,
> > 2) Having your corporate laptop get backed up to the company's backup
> >    server,
> > 3) Many general-purpose VPN tasks (file copying, etc),
> > 4) Online gaming (capable of creating a vast PPS load, along with fairly
> >    steady but low volumetraffic),
> >
> > etc.  P2P is only one example of things that could be stressful.
>   
> These things all happen - but they simply don't happen 24 hours a day, 7 
> days a week.   A P2P client often does.

It may.  Some of those other things will, too.  I picked 1) and 2) as
examples where things could actually get busy for long stretches of
time.

In this business, you have to realize that the average bandwidth use of
a residential Internet connection is going to grow with time, as new and
wonderful things are introduced.  In 1995, the average 14.4 modem speed
was perfectly fine for everyone's Internet needs.  Go try loading web
pages now on a 14.4 modem...  even web pages are bigger.

> <snip for brevity>
> >
> > The questions boil down to things like:
> >
> > 1) Given that you unable to provide unlimited upstream bandwidth to your 
> >    end users, what amount of upstream bandwidth /can/ you afford to
> >    provide?
>   
> Again - it depends.   I could tell everyone they can have 56k upload 
> continuous and there would be no problem from a network standpoint - but 
> it would suck to be a customer with that restriction. 

If that's the reality, though, why not be honest about it?

> It's a balance between providing good service to most customers while 
> leaving us options.

The question is a lot more complex than that.  Even assuming that you have
unlimited bandwidth available to you at your main POP, you are likely to
be using RF to get to those remote tower sites, which may mean that there 
are some specific limits within your network, which in turn implies other
things.

> >> What Amplex won't do...
> >>
> >> Provide high burst speed if  you insist on running peer-to-peer file sharing
> >> on a regular basis.  Occasional use is not a problem.   Peer-to-peer
> >> networks generate large amounts of upload traffic.  This continuous traffic
> >> reduces the bandwidth available to other customers - and Amplex will rate
> >> limit your connection to the minimum rated speed if we feel there is a
> >> problem. 
> >>     
> >
> > So, the way I would read this, as a customer, is that my P2P traffic would
> > most likely eventually wind up being limited to 256kbps up, unless I am on 
> > the business service, where it'd be 768kbps up.  
>
> Depends on your catching our attention.  As a 'smart' consumer you might 
> choose to set the upload limit on your torrent client to 200k and the 
> odds are pretty high we would never notice you.

... "today."  And since 200k is less than 256k, I would certainly expect
that to be true tomorrow, too.  However, it might not be, because your
network may not grow easily to accomodate more customers, and you may
perceive it as easier to go after the high bandwidth users, yes?

> For those who play nicely we don't restrict upload bandwidth but leave 
> it at the capacity of the equipment (somewhere between 768k and 1.5M).
> 
> Yep - that's a rather subjective criteria.   Sorry.
> 
> > This seems quite fair and
> > equitable.  It's clearly and unambiguously disclosed, it's still 
> > guaranteeing delivery of the minimum class of service being purchased, etc.
> >
> > If such an ISP were unable to meet the commitment that it's made to
> > customers, then there's a problem - and it isn't the customer's problem,
> > it's the ISP's.  This ISP has said "We guarantee our speeds will be as
> > good or better than we specify" - which is fairly clear.
> 
> We try to do the right thing - but taking the high road costs us when 
> our competitors don't.   I would like to think that consumers are smart 
> enough to see the difference but I'm becoming more and more jaded as 
> time goes on....

You've picked a business where many customers aren't technically
sophisticated.  That doesn't necessarily make it right to rip them
off - even if your competitors do.

> > One solution is to stop accepting new customers where a tower is already
> > operating at a level which is effectively rendering it "full."
> 
> Unfortunately "full" is an ambiguous definition.    Is it when:
> 
> a)  Number of Customers * 256k up = access point limit?
> b)  Number of Customers * 768k down = access point limit?
> c)  Peak upload traffic = access point limit?
> d)  Peak download traffic = access point limit?
> (e) Average ping times start to increase?
> 
> History shows (a) and (b) occur well before the AP is particularly 
> loaded and would be wasteful of resources.

Certainly, but it's the only way to actually be able to guarantee the
service you've promised.  If you were to choose to do that, the remainder
of this becomes irrelevant, because you're able to deliver your promised
service level.

> (c) occurs quickly with a 
> relatively small number of P2P clients. 

(c) is probably the (current) hot spot for determining this, in your
particular situation.

> (e) Ping time variations occur 
> slightly before (d) and is our usual signal to add capacity to a 
> tower.   We have not yet run into the situation where we can not either 
> reduce sector size (beamwidth, change polarity, add frequencies, etc.) 
> but that day will come and P2P accelerates that process without 
> contributing the revenue to pay for additional capacity.

Then you've effectively made poor choices, in that you're using a limited
technology, Internet bandwidth demands continue to increase (and will
continue to increase, for reasons above and beyond P2P), and you've
promised customers a level of service that you cannot deliver without
relying on a level of overcommit that will apparently be untenable in the 
future.

Am I missing anything?

Oh, yes.  The next question is one of ethics.  What do you do next?  Do
you propose to silently rip them off by rate limiting above and beyond
what you've guaranteed?  Do you force a change in their terms of service
upon them, knowing that they're locked into a term with you?  Do you 
change the promises that you're making to new customers?

> As a small provider there is a much closer connect between revenue and 
> cost.   100 'regular' customers pay the bills.   10 customers running 
> P2P unchecked doesn't (and makes 90 others unhappy).
> 
> Were upload costs insignificant I wouldn't have a problem with P2P - but 
> that unfortunately is not the case.

Then what you are promising customers is directly in conflict with what 
you are able to deliver.  This is a problem with your business plan.

Ultimately, I believe that service providers will need to establish what
the minimum service level is that they'll be able to provide to customers.
In my opinion, this is best done reflecting what you can deliver based on
every customer running full blast, because really, we don't know what the
next killer app will be.  I suspect it will be something devastating (to
network operators) such as TiVo downloading content over the Internet.

That isn't saying that you must build your network, /today/, to support
it - but you need to make sure that you can build your network up fairly
quickly to do so, and that you can afford to remain in business once you
have done so.

As an example, if you have max 1.5M uplink from your tower, can't expand,
and you've got 20 customers on that tower, you may be able to deliver 
256kbps upstream to the 5 full time P2P'ers in that customer base today,
but you can't actually deliver 256kbps upstream to 20.  Promise the 64kbps,
and you can deliver that, with room to spare.

Marketing doesn't like that?  Then tackle it from a technical angle.
Promise the 256, and /find/ a way to deliver it, if and when it becomes
an issue.

<other possible solutions omitted, there are none where everybody is
happy>

Otherwise, admit defeat, just be honest and say you're not going to honor
the promises you've made to your customers, and then limit them.  The high
bandwidth users either decide to put up with it, or they go elsewhere.  As
time passes, more and more customers who want to be in the high bandwidth
boat go elsewhere (i.e. to a competitor with a better network).  Maybe your
business eventually folds.  Maybe not.

Nobody said it was easy.  :-)

... JG
-- 
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.



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