Interesting People mailing list archives
Re: Interesting -- comment from author -- F.C.C. to Look at Complaints Comcast Interferes With Net - New York Times
From: David Farber <dave () farber net>
Date: Wed, 16 Jan 2008 02:05:16 -0800
________________________________________ From: Bob Frankston [Bob19-0501 () bobf frankston com] Sent: Wednesday, January 16, 2008 12:18 AM To: richard () bennett com; 'Bob Frankston' Cc: David Farber; 'ip'; 'Lauren Weinstein' Subject: RE: [IP] Interesting -- comment from author -- F.C.C. to Look at Complaints Comcast Interferes With Net - New York Times Perhaps it's one of those things where you had to be there before there were networks and were just copper wires and radios. When Dave Farber was playing with token rings and Bob Metcalfe was putting the Aloha net on a Coax as his class project. TCP is a neat hack but is not at all fundamental. You should also look at the history of UUCP You need to be careful about confusing end-to-end with womb-to-tomb. End-to-end means you don't assume anything but if you're lucky you'll get a few packets through and then can discover what works and drive the dynamic. The network is not any more fundamental to networking than rails are to travel. The wired home network is copper -- it’s not a network as such. It's just a metal we use to simply exchanging packets and it's not even necessary as we become more adept at using radios. An important point of end-to-end is that you don't serve the social needs in the network -- other than by facilitating people finding their own solution that is, essentially by definition, beyond your imagination. This is why I cite Minitel as an example -- it was farsighted but eventually the future veered off in a different direction. This is why adaptionism not only doesn't work in evolution but would frustrate the process by locking it into a local optima. Perhaps reading http://www.frankston.com/?name=VONRailroads and http://www.frankston.com/?Name=OurCFR might be a start. -----Original Message----- From: Richard Bennett [mailto:richard () bennett com] Sent: Tuesday, January 15, 2008 23:07 To: Bob Frankston Cc: dave () farber net; 'ip' Subject: Re: [IP] Interesting -- comment from author -- F.C.C. to Look at Complaints Comcast Interferes With Net - New York Times Please see my comments in-line. Bob Frankston wrote:
After writing this I Richard�s letter that distinguishes between
�Internet Congestion� and �Fairness� � that certainly sounds like a
moral distinction rather than a technical distinction. Please define
fairness.
Network fairness is something like pornography, we can't always define it precisely but we know it when we see it. In most of the fora where this has been an issue, such as IEEE 802, we've tended toward a set of definitions that would make Utilitatrians of the Bentham/Mill school happy: "the greatest good for the greatest number." But we're typically not that philosophical and simply true to prevent particular network stations from starving others. This has been a concern of LAN designers throughout the last 30 years of network engineering, Bob, and it's not a "carrier-centric" concern. Ethernet, Token Ring, Token Bus, WiFi and UWB all have fairness engineered into their media access control layers. No network engineer worth his paycheck wants to deploy a system in which one hungry station can effectively block network access for others, either through accident or design.
A good engineer works within the limits given � a very good engineer
questions the limits (and gets fired).
This is a very cute remark, and I liked it even better in your NN Squad formulation, where you added "...because the constraints serve a policy need higher than mere science or reality." I'll confess that science and reality bias my perspective on network architecture. I have this eccentric belief that networks that function well - meaning they're fast, robust, and inexpensive - serve the social needs of liberal democratic society better than those that don't function well. I haven't verified this belief, and I am aware that it's not universal. The Amish, for example, aren't at all into Ethernet or WiFi, although they have apparently embraced cell phones. The argument that all good engineers are unemployed is certainly novel, I have to admit. And I do hope you're aware that some limits are imposed by laws of physics that serve no particular political agenda.
I can understand that from a carrier-centric point of view there are
hogs that upset their resource allocation models. The question is not
whether the Internet needs a fairness system � the question is whether
the Internet as an emergent property of the end-to-end constraint can
even define such a concept and who do we get along so well despite the
lack or, perhaps, because of the lack of an imposed notion of
fairness. This is indeed echo of calling modem users hogs.
This is a very disappointing remark, as you're resorting to name-calling when we might be having an interesting discussion; it's not just carriers who care about fairness, of course, but by invoking the devil you're surely hoping to avoid serious discussion. As the Internet being "an emergent property of the end-to-end constraint," my goodness, there must be something more basic to it than the TCP error-recovery and flow-control mechanism. Consraints, you see, don't do anything unless there'a a prior reality to be constrained, and that would be the mesh of routers, packets, and links that hold it all together. You're going to have a hard time applying end-to-end constraints if you don't have any packet delivery mechanism. And whether we have modems or not, the essence of any packet-switched network is the shared data link. This was the deal, remember, that made it interesting to investigate the utility of packet-switching to begin with: if we relax the hard allocation limits of circuit switching and instead create a massive pool of bandwidth that we can all draw against, might not there be some interesting implications? And certainly hogging is one of them, just as bursting is another. Rationalizing the bandwidth needs of diverse applications against a common pool of bandwidth is what this whole Internet experiment is all about.
I�m responding with a caveat since a full response would be much
longer and I only want to touch at some top level issues which are
more policy than a particular algorithm. This is the
Malthusian/zero-sum issue. Malthus did argue that we have a finite
buffet and we�re going starve if we�re not very careful � we must
allocate the scarceness rather than creating abundance. This doesn�t
mean there aren�t limits but we shouldn�t hobble ourselves by focusing
only on the limits.
We network engineers certainly do care about limits, but I don't think it's fair to accuse of being obsessed with them. Certainly, we make our living by changing them. The Ethernet folks didn't just sit back and collect royalty checks after the 2.94 Mb/s Experimental Ethernet was installed at PARC, they went on a did the Blue Book, then the twisted pair versions that were practical to install and manage, and the 100 Mb/s version, and so on. But network administrators certainly do have to live within the limits of their budgets and purchasing options, this being a material world and all.
The idea that a �hog� blocks others makes this sound like a 200 car
train that blocks a track � if anything we have 200 independent cars
with others getting between them. The question is what opportunity or
percentage of slots each participant gets. You can have a local
algorithm to allocate a percentage of this capacity but that doesn�t
scale to large networks.
Most of the recent complaining about network neutrality violations has actually been layer two, private network concerns. The Comcast affair, for example, arose (in my opinion) because of the comany's concern about congestion in the upstream first-hop caused by a relatively small number of BitTorrent users. Their application of a "local algorithm" got a lot of people excited because they used some layer four protocols to implement it. So we can't just pretend that nobody cares about "local algorithms" when the evidence before us says otherwise.
What does it mean to �connect to an ISP�? If a carrier allocates a
ratio of 1:50 or 1:10000 for capacity allocated to each subscriber vs
the capacity to the rest of the network (through a thin peering
orifice) then complains when some take more than their percentage � is
that false advertising or na�ve modeling? What makes this problem more
difficult is that it doesn�t allow for local traffic to take advantage
of local abundance while backbone capacity is artificially limited to
create value through scarcity. As one drills down on this any policy
depends on an arbitrary definition of �fairness� and a guess as to how
this interacts with the network as a whole?
It's certainly the case that ISPs - and I'm using the term to denote "first mile network infrastructure providers" actually - have to model expected patterns of usage to get the most of their networks. We have asymmetric DSL and even more asymmetric DOCSIS because the usage patterns that undergird the models are old and new symmetric applications have shot them full of holes. The carrier response is partly counter-measures such as RST spoofing, but it's also transition to newer standards and better models, such as Comcast's announced plan to roll out 100 megabit symmetric service.
Again, the real question is why we are focusing on scarcity? If a
fiber to the home is about $1k (and going down or far less if I share)
then we could finance that at $50/month and pay it back fairly
quickly. Instead we pay that amount for 1/1000^th capacity or less?
And then we�re told we�re hogs? What percent of the local physical
facilities are allocated to the carriers� own use. If Verizon can
delivery multiple VoD streams over a 20Mbps connection then why are we
fighting over a few megabits shared among users? Why aren�t we asking
why we don�t have more capacity per connection?
Some of us have asked those questions, and the general answer has been (if you're paying attention) that upgrades are coming. In fact, all the ISPs are more or less constantly adding capacity, so the question is whether they're adding it fast enough to satisfy their customers and slow enough to satisfy their investors. This being a capitalist world, that sort of a balance is to be expected. Verizon has been a real trailblazer in bringing high bandwidth to the home, and I wish more telcos and cablecos were like them.
The question is not whether we get our fixed percentage but what we
can do with what we can get independent others� use and what we can
come to expect.
For now the high order bit is scarcity created by policy � it is not
scarcity created by so-called hogs. Unless you�re willing to talk
about the biggest hogs � carriers who think they own our ability to
communicate.
And I haven�t even addressed the whole idea of containing packets to
partitioned paths nor the lack of wireless connectivity nor �
I appreciate your idealism, Bob, as I'm a child of the sixties and big fan of Cheech and Chong. But we do have to be realistic on occasion, even thought it's boring. I hope this helps. RB
-----Original Message-----
From: David Farber [mailto:dave () farber net]
Sent: Monday, January 14, 2008 18:21
To: ip
Subject: [IP] Interesting -- comment from author -- F.C.C. to Look at
Complaints Comcast Interferes With Net - New York Times
________________________________________
From: Richard Bennett [richard () bennett com]
Sent: Monday, January 14, 2008 4:23 PM
To: David Farber
Subject: Re: [IP] Re: F.C.C. to Look at Complaints Comcast Interferes
With Net - New York Times
As the author of the article in question, I'll gladly defend it. The
fundamental point I was trying to make is simply that there's a huge
hole in the architecture of the IETF protocol suite with respect to
fairness. I'm a layer two protocol designer (Ethernet over UTP, WiFi 11n
MSDU aggregation, and UWB DRP are in my portfolio), and in the course of
my career have devoted an embarrassing amount of time to engineering
fairness in network access. Most the younger generation takes it as
given that if you understand TCP/IP you understand networking, but in
fact most of the progress in network architectures over the last 30
years has been at layers 1 and 2. And with the TCP-centric mindset, they
tend to believe that all problems of networking can be solved by the
application of the right RFCs. But in fact we all connect to our ISP
over a layer 2 network, and each of these has its own challenges and
problems.
The carriers are often criticized for not using packet drop to resolve
fairness problems, but that's not really the scope of packet drop, which
is actually a solution to Internet congestion, not to the lack of
fairness that may (or may not) be the underlying cause of the
congestion. We need a different solution to fairness at layer 3,
especially on layer 2 networks like DOCSIS where packet drop closes the
door after the horse has run off.
The buffet analogy needs a little refinement. What the bandwidth hog
does is block the line to the all-you-can-eat buffet so that nobody else
can get any food. That's not a behavior that would be tolerated in a
restaurant, and it shouldn't be tolerated in a residential network.
Unfortunately, it wasn't the huge problem when DOCSIS was designed, so
the 1.0 and 1.1 versions of the technology don't address it, certainly
not as well as Full-Duplex Ethernet, 802.11e WiFi, and DSL do.
Some may argue that the Internet doesn't need a fairness system as it's
mostly a local problem, and I have some sympathy for that point of view.
But in the final analysis, we all know that some of our bits are more
important than others, and the network will work better if the layer 3
and layer 2 parts can communicate that sort of information between each
other.
I don't view this as a moral problem as much as an engineering problem.
Moral philosophy is certainly a fascinating subject (as is video
coding), but it's outside the scope of the current discussion.
RB
David Farber wrote:
________________________________________
From: Bob Frankston [bob37-2 () bobf frankston com]
Sent: Saturday, January 12, 2008 1:01 AM
To: David Farber; 'ip'
Subject: RE: [IP] Re: F.C.C. to Look at Complaints Comcast
Interferes With Net - New York Times
Moral court again ...
Does this mean I can't share files with my neighbor because of the
cost of peering with a remote provider? Will someone judge that
backing up over the net is not an appropriate use of the network? Am I
not allowed to backup to peers?
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