On Sun, 19 Mar 2006, Dana Spiegel wrote:
> You bring up some good points. Let me see if I can tease out the
> logic here, because I think that you (and I'm sure many others) are
> confused about what Net Neutrality really means.
>
> When we speak of internet access, there are really 3 separate
> components we are talking about:
>
> 1) The backbone - the massive pipes that carry all of the traffic of
> the internet, and connect ISP to ISP (these are mostly fiber optic)
You mean "IP transit". Yes, it is a very important thing to discuss, but
I'm not sure if it is in the scope of this discussion.
Big carriers (such as AOL's network arm, ATDN), AT&T, Layer(3), GX, and
many others refuse to openly peer ("settlement-free interconnection") with
smaller carriers. This rarely has anything to do with the 'incumbency' or
'monopoly' status of these large carriers - in fact, (3) and GX are CLECs
and do not have a monopoly in any market they are operating.
I could talk more about this, but I'm not sure if this is something that
should be discussed in context of neutrality. There has *never* been any
allegations that large carriers engage in anti-competitive activities on
their network by blocking traffic. (Depeering discussions aside - I can
give a talk on all of those, but this would take me an hour to explain how
'teh intarweb' really works).
> 2) The last mile - the lines that connect end users (thats you, me,
> and google) to the backbone (these are cable, copper, and fiber, and
> sometimes wireless-Wi-Fi/WiMax/EVDO/etc.)
>
> 3) The internet service that runs on the last mile - THESE are ISPs like
> bway, pilosoft, and aol, and these companies DO NOT own the physical
> lines that make up the last mile
Actually, to be precise (and coincidentally, match the OSI layer diagram),
three things: (I'll use letters to avoid confusion with your numbering).
This is important because you are forgetting about "layer 2" services and
how they are different from "layer 3" services.
a) "layer 1" services, also known as the last mile - physical
infrastructure, copper, etc. It is pretty much either a monopoly or
wireless. The "competitive" infrastructure (CLEC-lit buildings) is
minimal, and can be ignored for purposes of neutrality discussion.
Examples: Verizon the ILEC, TimeWarnerCable
b) "layer 2" services (companies like VADI or Covad) - ones who buy
provide connections to ISPs but themselves do not provide any IP services
or internet connectivity.
Examples: VADI (Verizon Advanced Data, who we buy from), Covad, DSL.Net,
TimeWarner
c) "layer 3" services - companies that actually provide end-user-usable
product, namely connectivity to the internet.
Examples: Pilosoft, AOL, RoadRunner, Bway.net, NYCT, etc.
> some ISPs are (1) and (2) (WISPs especially, as well as Verizon and
> cablecos).
>
> (1) is mostly AT&T (before SBC bought it) and MCI Worldcom (was
> UUNET, now owned by Verizon), Sprint, and Level 3.
>
> When (1) and (2) were separate companies, and when internet services
> weren't converging with phone and tv services, Network Neutrality was a
> given, because the marketplace where all the (2)s were competing and
> purchasing capacity and carriage from the (3)s ensured that no single
> (2) could exert unfair market power.
Almost. Network neutrality was a given because "layer 2" companies
*cannot* (even if they wanted to) to mess with the traffic, it simply
isn't visible to them at the service they provide.
> Then we had Vonage and other VOIP, which is a service that works better
> when its packets are prioritized over other data packets. This points to
> a need for a small reconfiguration of packet carriage, and with a basic
> upgrade, all (1)s, (2)s, and (3)s can respect prioritization of some
> data packets over other data packets based entirely on the packet
> headers. There is a standard IP extension, 802.1p
> (http://en.wikipedia.org/wiki/Quality_of_service), and all business
> level, many consumer level, and all backbone level equipment can process
> data that contains 802.1p optimization.
Yeah, but you are missing one point - Layer 2 equipment normally does not
care about your IP QoS tags, and it needs to be manually explained which
tags to trust and which tags to ignore. Also, services that "Layer 2"
companies provide are usually price-differentiated, with regard to QoS
support or not.
I've previously given an example: VADI's standard ADSL product is
transported on their network as "UBR" (unspecified bit rate - best effort
service). I can also buy their SDSL product, which is transported as
VBR-nrt (it is best effort, but prioritized above UBR traffic).
Note that you are (maybe unintentionally) confusing multiple things in
your statements. 802.1p is not "IP extension" - it is extension of
ethernet standard (layer 2). It does not exist altogether beyond your
specific ethernet link. 802.1P specifies 3 bits (called "Class of
Service").
IP QoS is not 802.1p. IP header specifies 3 bits (so up to 8 possible
settings) and is called "Type of Service" (ToS) or "IP Precedence". When
you are discussing prioritizing packets on your own IP network, you
generally refer to it as "Class of Service" (CoS) and the process is
called "ToS-QoS" mapping.
Also, another point of note is that on each layer 2 link that is used for
transport of layer 3 traffic, there needs to be translation from L3 ToS to
L2 QoS (if any exist).
Now, the actual act of prioritizing traffic is complex. Usually, the given
piece of networking equipment has a limited number of queues (and
certainly always less than 8 - the maximum number under both IP and
ethernet). So, the act of allocating bandwidth among queues has to be done
manually, along with specifying which ToS/CoS corresponds to which queue.
As a result, you are entirely wrong about backbones 'processing' IP ToS
tagged frames - no carrier that I know does respect user-set IP ToS tags
with regard to queueing. All IP transit is "best effort". (exceptions are
certain carriers offering IP-VPN, but that's beside this discussion, and
its not "transit" anyway).
So, what is the bottom line about QoS in real world? It does not exist,
beyond given carrier's network, as specified by carrier's networking
staff and defined by carrier's business needs, available technologies and
equipment.
Expectation of end-to-end QoS is a daydream.
Hm, maybe I should give a talk about what QoS really means and how (and
whether) it really works, end to end. :) You can start here for more
information:
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/qos.htm
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat2940/12119ea1/2940scg/swqos.htm
> This is part 1 of Network Neutrality: any service that requests QoS,
> when carried by a (1), (2), and (3) that can route and handle 802.1p,
> should respect and follow such packet instructions, regardless of the
> origin or destination of the packet, so long as it doesn't damage the
> routing of other packets. In the case of pilosoft, Alex, this means that
> you certainly can provide pilosoft VOIP service, and the packets that
> carry that service should be optimized appropriately. But, by putting
> into place equipment that provides this functionality, you must also
> appropriately process any other QoS optimized packets, even if they
> don't originate or terminate with you.
How about..."Heck no, I won't, pay me".
a) This would allow dishonest customers to set their routers to mark all
packets with high QoS and as result, get "priority" service over other
customers paying the same amount. Why should I permit that?
b) I'm already paying to "Layer 2" carriers (like VADI) more money for
guaranteed prioritized traffic. If a customer wants guaranteed service, he
can pay me more, in turn, I will pay VADI more, and he'll have it. Even
if I prioritize packets on my network (which I won't do) - customer is
likely to run into congestion on VADI's ATM backbone before they run into
congestion on my network. And, because of above, this will render
end-to-end QoS worthless.
c) Internet is "best effort". We sell Internet Access, which is "best
effort". We won't molest your packets, but, we also won't honor anything
you will demand as "better than best effort" without you actually paying
us for this service.
d) Even assuming I want to go along with it, this would require me knowing
which QoS (IP and ethernet) tags does Vonage (and every other of 123456
fly-by-night VoIP providers) equipment use, making sure that if I honor
their tags I won't degrade the "best effort" service for other customers,
and won't degrade "guaranteed" services for customers who are buying that
from me.
In other words, it is simply impossible for me to do this properly. And,
if I can't do it properly, there's only one answer: "best effort".
> As a consumer, this is important because it means that, even though you,
> as my ISP, may provide VoIP service, I am not required to only get such
> service through you. You can offer benefits if I do buy through you,
> such as discounts/bundling or converged billing or enhanced voicemail
> that delivers directly to my email inbox. But you cannot leverage your
> status as an ISP to offer an optimized service and block that same
> optimization from being used by a third party service.
Why won't I? I sell 'best effort'. You buy 'best effort'. I also sell
'Pilosoft VoIP' which is guaranteed. You want Vonage? Buy from someone who
prioritizes Vonage.
Vonage's business model is built on trying to provide telephone service
through a 'best effort' network. It looks very silly of them to try to
demand others to bend over and provide a different service to Vonage than
they provide to every other piece of Internet traffic.
Yes, ultimately, Vonage's business model is built on making customers
accept lower price in exchange for crappier voice connection. And I think
this model is a path to failure. But that's beside the point.
> Continuing on, SBC bought AT&T and Verizon bough MCI Worldcom. Now,
> two of the biggest backbone networks are owned by the two biggest
> telcos. (1) and (2) are now the same company. So the marketplace
> dynamics that ensured that no (2) could leverage unfair market power
> over another (2) in terms of backbone traffic.
>
> This is part 2 of Network Neutrality: backbone providers (1) cannot
> leverage their ownership of last mile networks (2) (funded by taxpayers
> to the tune of $2000 per person over the past decade or so) to favor or
> discourage traffic from any origin to any destination. This means that
> if I pay for a 5mbps connection, I can use that 5mbps connection for
> whatever traffic I choose, so long as it doesn't damage the network, to
> its fullest capacity. This also means that if Google pays for a 1gbps
> connection to the backbone, whatever they pay for that connectivity also
> pays for carriage to any endpoint, to the fullest extent of the capacity
> of the network, without the threat that their traffic will be
> artificially reduced in capacity or speed due to failure to pay
> additional fees for entry to a network.
The above statement really shows you don't understand how internet works
(peering/transit/etc), what 'best effort' really means, what is a
'backbone', and who pays whom on the internet.
Unfortunately, I already spent an hour writing a explanation of
ToS/QoS/CoS, and this will wait till I have another hour of spare time -
along with the response to the rest of the email. :)
> Alex, this is the part of Net Neutrality that has absolutely nothing to
> do with how you operate your "network", except that it will prevent AT&T
> and Verizon from unfairly competing against you using their ownership of
> both backbone and last mile connectivity.
>
> What Verizon and AT&T are likely to do (especially since they publicly
> stated about as much), is that they will require Google and others to
> pay additional fees to get higher speed access to their end user
> networks. They will be able to do this since they own the networks
> between Google's ISP and the end user. Since you (and all other ISPs)
> don't own any backbone, you can't offer this enhanced speed access for
> Google and other content providers over your network. You are stuck
> getting the slow speed version. And given all of the past behavior of
> the telcos, this is exactly what they would do with this power.
This is somewhat confusing. VZ and ATT haven't specified just what exactly
'higher speed access' entails. Do they mean 'no settlement-free
interconnections' or something else. Anyway, wait for the part 2 of the
response. :)
> This wouldn't be an issue if SBC and Verizon didn't own the backbone,
> since the backbone providers either would never offer this optimized
> service, or would offer it equally to you and SBC/Verizon.
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