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Comcast Outlines New Broadband Policy
Slatterz writes "US cable provider Comcast has presented its long-term solution for managing broadband traffic. The new system is set at putting to bed a minor scandal that erupted around the company when it was found that Comcast deliberately limited traffic for certain applications. The company said that under its new system, traffic will be analyzed every fifteen minutes. Users who are found to be occupying large amounts of bandwidth will be placed at a lower priority for network access behind users with less bandwidth-intensive traffic. The new system will not replace or be related to the company's earlier installment of bandwidth caps, which limited a user's data intake to 250GB per month."
I don't know what you're talking about. Where I live, I have two options.
Beats my old options: Comcast, unreliable ISDN, or 12.6Kbps dial-up.
My take on this? It's a much better policy than just randomly killing connections that look like they might be doing something that may be using large amounts of bandwidth.
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
The types defined in the RFC are:
I believe an extension also had a "maximize security" option as well.
Alas, almost nothing supports these flags, and I believe a later RFC has proposed reusing the QOS bits in the IP header for an incompatible use.
set up mrtg to poll your router and make your own graphs.
"We returned the General to El Salvador, or maybe Guatemala, it's difficult to tell from 10,000 feet"
That's probably not throttling. Same thing happens to my cousin, and the same thing happens to me (though not as bad.) Every seed and leech in that torrent is still hammering your connection and timing out, requesting what parts you're advertising. At least that's what my firewall logs seem to suggest.
Power cycle your cable modem and get a new IP address. Your former cloud will no longer be DDoSing your connection.
DATABASE WOW WOW
its called "class action lawsuit" - it works !
Read radical news here
Here's an email from one of Comcast's engineers recently sent to Dave Farber's Interesting People mailing list. It clarifies the policy quite well:
From: "Livingood, Jason"
Subject: Clarifying Misconceptions of the New Comcast Congestion Mgmt Syste
Hi Dave
I wanted to try to clear up a misconception about how the new Comcast congestion management system works. I believe we have both heard people complain that they fear that they will be unable to use their provisioned speeds during off-peak hours, for example, or at all times of the day, or that users are somehow throttled to a set speed. Neither of these two things are correct. Part of the problem appears to be confusion over how a user's traffic enters a lower priority QoS state, so I hope to clarify that here
In order for any traffic to be placed in a lower priority state, there must first be relatively high utilization on a given CMTS port. A CMTS port is an upstream or downstream link, or interface, on the CMTS in our network. The CMTS is basically an access network router, with HFC interfaces on the subscriber side, and GigE interfaces on the WAN/Internet side. Today, on average, about 275 cable modems share the same downstream port, and about 100 cable modems share the same upstream port (see page 5 of Attachment B of our Future Practices filing with the FCC, available at http://downloads.comcast.net/docs/Attachment_B_Future_Practices.pdf). We define a utilization threshold for downstream and upstream separately. For downstream traffic, a port must average over 80% utilization for 15 minutes or more. For upstream traffic, a port must average over 70% utilization for 15 minutes or more
When one of these threshold conditions has been met, we consider that individual port (not all ports on the CMTS) to be in a so-called Near Congestion State. This simply means that the pattern of usage is predictive of that network port approaching a point of high utilization, where congestion could soon occur. Then, and only then, do we search the most recent 15 minutes of user traffic on that specific port, in order to determine if a user has consumed more that 70% of their provisioned speed for greater than 15 minutes. By provisioned speed, we mean the "up to" or "burst to" speed of their service tier. This is typically something like (1) 8Mbps downstream / 2Mbps upstream or (2) 6Mbps downstream / 1Mbps upstream
So how does this work in action? Let's say that a downstream port has been at 85% utilization for more than 15 minutes. That specific downstream port is identified as being in a Near Congestion State since it exceeded an average of 80% over that time. We then look at the downstream usage of the ~275 cable modems using that downstream port. That port has a mix of users that have been provisioned either 8Mbps or 6Mbps, so 70% of their provisioned speed would be either 5.6Mbps or 4.2Mbps, respectively. So let's use the example of a user with 8Mbps/2Mbps service on this port. In order for their traffic to be marked with a lower priority on this downstream port, they must be consuming 5.6Mbps in the downstream direction for 15 minutes or more, while said port is highly utilized
Once that condition has been met, that user's downstream traffic is now tagged with the lower priority QoS level. This will have *no* effect whatsoever on the traffic of that user, until such time as an actual congestion moment subsequently occurs (IF it even occurs). Should congestion subsequently occur, traffic with a higher priority is handled first, followed by lower priority (and this is not a throttle to X speed)
I hope this helps. You can others can feel free to contact me directly if you have any questions
Regards
Jason Livingood
- Engineering & Technical Operation
For verification, you can find the original in the IP Archives. Date of the email is 2008-09-24 12:37:35
"The legitimate powers of government extend only to such acts as are injurious to others." Thomas Jefferson.
If you seriously think you are going to exceed 250GB a month, spend the extra money and get a business account. If you are that heavy of an internet user, moving to 70 bucks a month or so shouldn't be that big of a deal.
Guess what, I have the Comcast Business 16/2 Account at home - and we got the "You now get 250GB of monthly bandwidth " e-mail just like everyone else....