

Video streaming & net neutrality - dalton
http://ber.gd/post/22374588073/video-streaming-net-neutrality

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modeless
This better get investigated at least as thoroughly as the Street View WiFi
thing. Unlike that situation, this is actually causing quantifiable harm to
consumers right now (as Comcast would otherwise actually be forced to raise
their data caps to provide this service, improving consumer choice by making
alternatives more viable).

~~~
seanp2k2
>"improving consumer choice by making alternatives more viable"

And that's exactly what they're afraid of.

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slapshot
To be clear, this is a discussion of "net neutrality" in that the author
alleges that Comcast is prioritizing (and not charging for) traffic for its
Xbox streaming media application, which works like a Video-on-Demand service.
Comcast claims that this is similar to a standard Video-on-Demand service
based in a cable box and can legally be prioritized because it is the
functional equivalent of traditional VOD. Comcast doesn't see anything wrong
with not charging for bandwidth used for set-top-box VOD, and analogizes that
to Xbox VOD, even though the two may use different underlying technologies.

The author says that it shouldn't be treated like VOD because it is delivered
over an IP network rather than old-school cable and Comcast has no right to
prioritize video packets for its own IP video service over those for other IP
video services (e.g., Netflix).

Which is more "neutral" is an interesting question: neutrality over the
mechanism by which Comcast delivers its VOD service to cable subscribers, or
neutrality between IP-based video streaming services?

~~~
bdb
Hi. I'm the author of the original post; thanks for your comment.

To be clear, VOD streams to your STB are delivered over IP, just not through
your cable modem, router and home network. You're right, of course, that
Comcast claims these streams are no different than that VOD service.

The point where I think Comcast's argument falls apart is that streams to
their Xbox app are delivered through the exact same network elements both
inside and outside your home, as e.g., Netflix streams.

~~~
ismarc
This is a point that is frequently missed and ends up muddying the actual net
neutrality discussion. For cable providers, Internet (big I internet, not just
a network that uses the same protocols) is carried on certain channels with
vod and normal cable channels carried on other channels. For providers like
Uverse, it's not separate frequency channels, but separate vlans with
dedicated bandwidth on each (very similar model, though, big I internet
traffic is separate from other services). Where the neutrality line is crossed
is when all traffic on the big I Internet segment isn't treated equally. In
this case, the separation of billing is giving that traffic preferential
treatment over other big I Internet video streaming.

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tonyb
The DSCP values have nothing to do with the bandwidth cap. DSCP is just a
"flag" on the packet and most internet routers don't look at that at all. I
would also be very shocked if DSCP has anything at all to do with the way
Comcast is calculating your bandwidth cap. They are most likely using
something like IPDR or subscriber-aware DPI.

DSCP values also are completely separate from DOCSIS priority on the cable
network. With DOCSIS the provider can create service flows with different
priorities and bandwidth restrictions. Most providers only use two service
flows (one upstream and one downstream) but if Comcast wanted to give some
subset of traffic priority on the DOCSIS network (where they are most likely
to see congestion) they would put that traffic into a separate service flow
with a higher priority. That is how they do their "congestion management" to
top users, top users in saturated nodes get their service flow priority
temporary and dynamically reduced (via PCMM) so other users traffic gets first
shot at open time slots.

In addition, with DOCSIS 3 it is very possible for the MSO to add a dedicated
set of RF channels that only select traffic would use, which in this case it
would be the Xfinity video streams. I have no idea if that is how Comcast has
implemented this but if so how is that any different to Video-On-Demand on a
standard STB? With standard VOD on a STB there is a set of RF frequencies set
aside for VOD use. If they put Xfinity XBOX IP traffic on a separate RF
channel it would be no different than adding an additional RF channel for VOD
and would have zero impact on total available internet bandwidth to the cable
node.

~~~
modeless
The real problem here is that "net neutrality" is a farce as long as providers
are allowed to send their most lucrative services over non-neutral channels.

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zbisch
I'm sorry to sound very negative on the author, but I don't know how you could
have the knowledge to write this article, but not have the knowledge to
understand the basics of costs on the Internet.

A few points that are horribly wrong FTA (reasoning explained below):

"In order to use as few network resources as possible—both to keep costs low
and quality high—these providers typically attempt to get as “close” as
possible to end users, often forging agreements in which they directly connect
to provider networks."

The "close"-ness that they are talking about here is not geographic closeness
but network closeness. And this isn't just in terms of the distance traveled
geographically, but the cost to send that traffic across some other network.
That is, it is more expensive for Netflix to send traffic from their provider
to (for example) AT&T to Sprint to Comcast to you, than it is to have Level3
send traffic from Level3 to Comcast to you. In fact, because of the peering
agreement between Level3 and Comcast, Comcast has to pay Level3 to send them
traffic (or so I believe).

The cost is not how many links it has to traverse, but the cost of the peering
agreement that that network has with where it is sending the traffic.

"The only appreciable differences between the Xfinity streaming service for
Xbox and e.g., Netflix, are that the source of content is within the Comcast’s
“internal” CDN instead of on a third-party CDN, and that Comcast requires you
to be using their own Internet service. (This is much more likely related to
their agreements with content owners rather than any technical reason.) "

This is wrong. The reason is entirely financial. It is cheaper for Comcast to
send traffic only within their network. If I traveled to China, it would cost
Comcast much more to send the traffic to China and almost nothing to send the
traffic to my computer which is Comcast's network.

"As you’ll see, the cap-exempt content is likely even more expensive for
Comcast to deliver than the third party content!"

"All of these third-party streams almost certainly originate from third party
providers in the Bay Area, all via direct connections to Comcast. Even though
they count against my bandwidth cap, they almost certainly traverse fewer
fiber route-miles and physical router ports (Comcast’s two primary costs of
delivery) than the stream which originated in Seattle(!) and does not count
against my cap."

Completely wrong.. Even though it is a further distance away, sending traffic
from Seattle to somewhere in California is almost no cost to Comcast, so long
as it stays within their network. With retrieving content from Level3 (such as
Netflix movies), it has to _pay_ Level3 to send them traffic that its users
want.

Again, sorry to bash on the author so much, but the author was misinformed
concerning cost. Also, DSCP is kind of meaningless when traveling between
networks (any network router can overwrite them and change their priority).

~~~
wmf
It has been reported that Level 3, Akamai, and Limelight are _paying_ Comcast
_and_ delivering content as close to the user as possible, so I agree with the
original author that external content would seem to be cheaper than Comcast's
internal CDN (maybe even a profit center).

[http://arstechnica.com/tech-policy/news/2011/02/peers-or-
not...](http://arstechnica.com/tech-policy/news/2011/02/peers-or-not-comcast-
and-level-3-slug-it-out-at-fccs-doorstep.ars)

<http://apps.fcc.gov/ecfs/document/view?id=7021030795>

~~~
zbisch
Ah, very good point. The last thing I read on the Level3/Comcast spat story
lead me to believe Comcast was paying Level3 for the peering. I apologize.
However, this line lead me to believe the author had a misunderstanding of the
costs of traffic:

"...they almost certainly traverse fewer fiber route-miles and physical router
ports (Comcast’s two primary costs of delivery)."

That is, unless the author meant Comcast's primary costs within their network,
which is not what I read it as. Without providing reference to the cost of the
peering, the comparing the _geographic_ distance of traffic seemed irrelevant.
Even in this case, the reason that it is more expensive for Comcast to send
traffic is not that is coming from Seattle, but because they are losing money
on having Level3 pay them.

Edit: I also need to read more on this as I'm curious why Level3 is paying
Comcast since Comcast is (as far as I know) not acting as a transit network.
But I suppose this is what happens when you violate valley-free routing.

Edit2: Also, just wanted to add, the fact that Comcast controls the peering
links is why this is so sketchy. By raising the costs of peering links, they
could make it way more expensive for the competitors to send their users
traffic, forcing the competitors to raise their prices, allowing Comcast to be
the only content provider to have reasonable prices. While the part about the
bandwidth to them not counting towards your cap is sketchy, the practice of
charging you less, a lower flat rate, or not at all for traffic that stays
within the network is reasonable. Where it is sketchy is when that difference
is leveraged to make the service cheaper. If the service is more expensive,
it's the fact they are charging competitors more that is sketchy. So... in
general, providing content and the network is all around sketchy.

~~~
bjornsing
Just a quick comment on cost (since OP and these comments seem to have it a
bit backwards):

The real cost in a DOCSIS network like Comcast's is actually in the last mile.
DOCSIS is sort of like a mobile network in a pipe. The base station in this
case is called a Cable Modem Termination System (CMTS) and data is transmitted
from there over RF with QAM modulation to all the cable modems on the same
coaxial segment. This can be hundreds or even thousands of cable modems. For
unicast IP the packet is only received by one of them but they all have to
listen.

When the radio spectrum inside the coaxial cable becomes congested the segment
has to be split in two parts and a new CMTS installed, very similar to how you
split a mobile network cell into sectors to improve capacity. Like with a
mobile network this is capital intensive.

Not saying this makes Comcast right. But important to understand where they're
coming from.

~~~
zbisch
Residential networks are actually part of my current research, and, although I
don't know the full details of every technology, I am familiar with the basics
of how DSL and DOCSIS networks work.

Yes, there is a cost (in terms of performance and congestion) over these
links, but this not really relevant in the discussion when talking about the
cost of where the traffic is originating. Whether the traffic originates in
Comcast's data center in Seattle, from a CDN in Level3's network, or over
their peering links with Tata, the cost of it traversing the last-mile is
irrelevant. In any of these cases, traffic will still be crossing this link.
And yes, this is a significant cost in terms of deploying the last-mile
network, but as I said, it has nothing to do with the cost of getting of
getting the packets to the DOCSIS network.

What we're saying is that if Comcast is carrying traffic from Seattle to a
user in their network, they do not have to pay a transit provider to carry
this traffic. If it is from Level 3, Level 3 would actually be paying them to
carry that traffic to Comcast subscriber. If the traffic were coming from
Comcast's peering link with Tata, Comcast would have to pay Tata (their
transit provider) for the traffic.

Yes, the cost of the last-mile network is real and important, however, in this
discussion it doesn't really relate, since you would be traversing the DOCSIS
network in all cases.

~~~
bjornsing
Well... Isn't there a fundamental assumption in the network neutrality debate
that cost per bit is zero or very low? At least that's the feeling I get from
reading this discussion. People seem to think that cost comes mostly from IP
transit, and implicitly that last-mile infrastructure cost is constant and
sunk.

Well, that assumption is wrong for mobile, and to some extent for DOCSIS.
Last-mile cost scales with traffic volume (and completely overshadows the cost
of IP transit). That's why I think you'll see MNOs and MSOs fighting the
hardest against network neutrality.

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nightpool
Can you change the title to match the actual article? I belive that the Hacker
News guidelines suggest to keep the submission title as close as possible to
the new one. (esp. in cases like "exhaustively researched")

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Locke1689
Check it again; you're wrong.

~~~
scott_s
From the guidelines: _You can make up a new title if you want, but if you put
gratuitous editorial spin on it, the editors may rewrite it._

I think that "exhaustively researched" counts as gratuitous editorial spin.

~~~
dalton
I gave the submission a different title specifically to call out it was
original detective work done over the course of several days by a
technologist... a technologist who is "showing his work".

The vase majority of press I read about net neutrality is done from a
theoretical or policy perspective, and tends to rely on research done by 3rd
parties. My aim was to distinguish that this particular post as not being yet
another post of that variety.

That being said, I am fine with the editors decision to change the title of my
submission.

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noobface
1\. It's possible to rewrite DSCP values at each hop.

2\. It is likely these DSCP values are not used for prioritization over other
services.

The most likely scenario in my mind: Comcast's trust boundaries could
encompass a large enough portion of their CDN to simply not re-write of the
DSCP values. Meaning this DSCP value may represent an internal network
prioritization, but not impact the traffic delivery outside of their data
centers. The traffic, because it originates within the trust boundary, retains
its previously assigned DSCP value, but it does not indicate what policies are
implemented in the actual delivery of the packet.

This post, while very interesting, simply cannot know with certainty that
comcast is prioritizing traffic without conducting an extensive test. We're
talking many gigabytes of traffic and many locations. However, this does
warrant testing as the DSCP values could easily be used to implement
prioritization.

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kozubik
How do the traffic exemptions in AWS fit into this net neutrality debate ?

There are quite a few ways in which traffic between different AWS components
is discounted[1], or "favored" over other traffic, and this doesn't bother me
a bit - it seems quite reasonable.

I lean (slightly) to the net neutrality argument, but I have a hard time
seeing how the billing practices of AWS are neutral within that framework.

How does the OP feel ?

[1] For instance, bandwidth between EC2 and S3 is free.

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recoiledsnake
I am shocked that everyone here seem to be ignorant of this very important
fact:

The Comcast XBox VOD is only available if you're already a paying customer for
Comcast Cable TV.

i.e You cannot just be a Comcast Internet subscriber without TV access and get
access to the VOD streams for $x/month which are cap exempt. If this was the
case, then it won't be net neutral. Thus Netflix can still compete on it's
price versus Comcast TV's price. This new service is just an added delivery
feature of Comcast TV.

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thespin
If others can replicate what the author did, then it might rise to the level
of "exhaustively researched".

If you are a Comcast customer, try to replicate the experiment yourself. See
if you get the same results.

"Set Top Box" == Black Box.

No doubt we'll soon see one for live video (Skype).

