Observing traffic prioritization in Comcast’s network | Hacker News Reader

Observing traffic prioritization in Comcast’s network

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104 pointsdalton27 comments

"Because the Xfinity traffic is mapped to a different DOCSIS service flow when prioritized, it is exempted from the downstream rate limit, so my total bandwidth usage stays consistently higher than my service tier would normally allow."

And? So what's the problem? That's sounds exactly right to me: The xfinity traffic runs over and above any bandwidth limits you have for your regular internet.

i.e. using xfinity has zero negative effect on your regular bandwidth.

Was that the point you were trying to make? That comcast is doing this right? Because if you were trying to accuse comcast of "prioritization of traffic in violation of the terms of the Comcast/NBCU Consent Decree." then your post proves exactly the opposite of that.

If you read the decree:

  If Comcast offers consumers Internet Access Service under a
  package that includes caps, tiers, metering, or other
  usage-based pricing, it shall not measure, count, or 
  otherwise treat Defendants’ affiliated network traffic 
  differently from unaffiliated network traffic.  Comcast
  shall not prioritize Defendants’ Video Programming or
  other content over other Persons’ Video Programming or
  other content.

It's not about Comcast using your bandwidth, it's about them offering services which third party providers "can't," because their traffic is not treated equally.

[edit: formatting]

Did you know that when you watch pay per view on your TV using comcast it runs on the exact same lines as your internet?

So are you saying comcast can not provide pay per view?

They can not prioritize the internet part of their service "network traffic", but as you yourself proved this service doesn't use your internet bandwidth, even if it uses TCP/IP. It runs using its own section of the cable line. It doesn't matter that it uses DOCSIS, or TCP/IP. Comcast is well within their rights to use their cable lines for TV service.

> it's about them offering services which third party providers "can't,"

Yes, that's true - comcast offers cable TV, and other providers can't. Shouldn't you be complaining about that too?

The difference is this: I pay for internet bandwidth - comcast can not then use that bandwidth in a way that prioritizes their own services. But if comcast wants to provide me extra bandwidth to my house, and then run a service over it, that's perfectly OK.

BTW you should get kudos for including all the data in your post. I'm arguing with you using the data that you yourself gave me, which isn't a great way to argue (I should really go and get my own data). So you get credit for that, but I'm sorry, your conclusion is just incorrect.

Most of your cable service's video is actually delivered over IP, but it is on dedicated RF spectrum, even though it's on the same physical wire. If Comcast wants to deliver video to my STB over separate channels, I don't care what protocol they decide to use.

However, if they're delivering video to a generalized computing device in my home, over my home Ethernet network, over the same downstream channels as Internet traffic, and further, they're prioritizing that traffic, that's different. If there was congestion in the last mile that wasn't just me hitting my rate limit with synthetic traffic, Comcast's traffic would be prioritized, and that's not right. It would be affecting your internet bandwidth. If Comcast had provisioned dedicated RF channels for handling this traffic, just as they do for your STB, then I could at least see your point, but that's just not the case.

[edit: typo]

It's only prioritized up till the cable modem, not after so that part doesn't matter (i.e. other providers have equal access to your home network).

And up till the cable modem it is basically using a different channel: They are increasing your allowed bandwidth to make up for the usage. To me that's indistinguishable from a dedicated RF channel.

On your last point, we'll have to agree to disagree. Good night! Thanks for the spirited discussion.

By prioritizing network traffic and running this over their same routers someone down the street using their XBox reduces my bandwidth without being part of any cap's, that's a real problem.

My advice is to stay away, far away, from Comcast. I wish I never had the misfortune of having to work with such an incompetent, corrupt organization. But alas, I am stuck in a year long contract that auto-renews without my re-authorization.

Sooo.... if comcast prioritizes Xfinity traffic at a DOCSIS level and not an IP level, it's not violating net neutrality?

hey Zac. I'm the author of the post.

That, or something like it, is Comcast's argument. Which makes no sense. This is a video streaming service, it's prioritized, and it's delivered just like other video streaming services are. Hopefully the data reflects this.

https://en.wikisource.org/wiki/Cable_Communications_Policy_A...

Cable transmissions are not 'internet video' transmissions. They are different. Your cable tv is a 'video streaming service' too. Xfinity tv is probably a cable communications ie. cable tv, not an internet communication (i.e. streaming tv). It's how you define it to the FCC.

I agree that Comcast is in fact trying to classify this service as a Title VI service. The implementation of this specific service seems to have far more in common with Netflix than standard cable service (even including VoD streams delivered to your STB.)

Whether the FCC considers this as a Title VI service or not is yet to be seen.

The key is that Comcast does not stream its conent to nomn Cable TV subscribers. If it did, it would bea violation, but this just seems like an alternative way of accessing Cable TV, which still needs to compete with Netflix/etc on price and content.

You need to be a Comcast subscriber to use their iPad app, but they don't have to prioritize traffic or exempt it from bandwidth limits for it to work.

Can a comcast Cable TV subscriber stream comcast content when they are not using their comcast line? Does it matter if they can?

> This is a video streaming service, it's prioritized, and it's delivered just like other video streaming services are.

So is pay per view. Rephrase your argument in such a way that pay per view is allowed and this isn't. You can't, because your argument is incorrect.

Pay per view is allowed, and so is this.

Maybe you got down voted due to tone, but I thought your comment was really valid.

I hope they legislate a more pure neutrality, but I can see how what you are saying allows them to continue this.

You can access Xfinity Streampix through the Xbox app. Streampix is an additional service which cost $4.99 per month and allows access to a library of tv shows and movies which can be viewed by customers on their PCs, Xbox360 and Apple mobile platforms. When Comcast gets around to adding streaming capabilities to their Android app presumably it will available their also.

Unlike Ondemand or pay per view pricing is not based on a per viewing or a predefined rental period. All content decisions are made by Comcast versus Ondemand where the content providers control what content is available and when it is available. For example HBO makes different content available via ondemand each month and the decision regarding which content is available is made by HBO and not Comcast.

It is like and intended to compete with Netflix and other Internet streaming services. It operates differently from traditional pay per view and content streaming services. It also is not like a traditional premium tv channel for which a monthly fee is paid. It is exactly this type of service the agreement was designed to prevent favorable treatment of versus the same type of service provided by someone besides Comcast.

The important part to this article isn't that they are doing this. Its that they are back tracking on their own statements of why the caps were needed in the first place.

If you remember when they were arguing for the caps the main reason was the cost to deliver to the last mile. This clearly shows that is not the case as they have given all of their customers additional bandwidth above and beyond their stated plans.

Kind of makes the reason for caps in the first place null and void.

When I load this on my iPad a white div appears and covers up the text after the page finishes loading. Anyone else?

Yes, same for me.

Hit the stop (x) after the content loads. Worked for me.

Yes - completely unreadable on an iPad for me, alas!

Fixed. Sorry!

So, hypothetically speaking, modifying traffic as it flows through a linux firewall in order to change the DSCP field to the values used by Comcast would be useful in avoiding the caps on traffic levels.

This article only looked at downstream traffic, so all the bandwidth management is done before you can touch the packets. On the upstream, Comcast is certainly re-marking (overwriting) the QoS values based on their own priorities.

Ohh netflix!! Think we have the solution for your problems....

Didn't mention what side of the traffic you do this on :)

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