Comcast's New Throttling Plan Uses Trigger Conditions, Not Silent Blocking

clang_jangle writes with this excerpt from The Inquirer outlining Comcast's new traffic-throttling scheme, based on information from Comcast's latest FCC filing. "Its network throttling implements a two-tier packet queueing system at the routers, driven by two trigger conditions. Comcast's first traffic throttling trigger is tripped by using more than 70 per cent of your maximum downstream or upstream bandwidth for more than 15 minutes. Its second traffic throttling trigger is tripped when the Cable Modem Termination System you're hooked-up to – along with up to 15,000 other Comcast subscribers – gets congested, and your traffic is somehow identified as being responsible. Tripping either of Comcast's high bandwidth usage rate triggers results in throttling for at least 15 minutes, or until your average bandwidth utilisation rate drops below 50 per cent for 15 minutes."

Comments

Re:Laws

[Saishuuheiki]

Here in america we prefer a system where the ISP gets a monopoly and can advertise what you could get, not what you will get ...sadly

Summary Backwards

[HoboCop]

I read the FCC paper.. the summary is full of errors. The individual user does not get throttled until the entire CTMS port is in a congested state (that's 80% downstream, 70% upstream). And 'throttled' is a loose term.. if the bandwidth is available you get it. You are throttled if there are lower volume users on the shared pipe, and even then they just get a higher priority. Depending on how bad the congestion is, you might not even notice this.

this is VERY old news, and its fairness

[nweaver]

Comcast rolled this out nearly a year ago.

And its not throttling, its a fairness mechanism: It means that light users won't get outcompeted by heavy users, but heavy users shouldn't get starved out unless things are really REALLY bad.

Oops, left something out

[sunking2]

This part is rather important, yet amazingly was left out of the summary.

During the time that a subscriber's traffic is assigned the lower priority status, such traffic will not be delayed so long as the network segment is not actually congested. If, however, the network segment becomes congested, such traffic could be delayed.

So what they are really doing is lowering your priority. If there is no real congestion then you notice no difference. If things get saturated then your packets are delayed before other peoples.

Re:So...

[gangien]

comcast can suck it. maybe off topic, but i just ditched them.

* they advertise how customers will need to do nothing for the digital conversion. then we get boxes
* they've lied to my mom about prices, she called up before she had somethign done, they insisted it was free of charge, then she got a bill with.. charges on it, now it's of course it's not free.
* internet sucks, last few months during the evenings i had lag spikes all the time.

i've switched to verizon fios and so far i like it better, plus it's a few bucks cheaper. hoepfully i'll continue to liek it

Just to be clear...

[fahrbot-bot]

From the actual PDF:

• ... create two Quality of Service ("QoS") levels for Internet traffic going to and from the cable modem: (1) "Priority Best-Effort" traffic ("PBE"); and (2) "Best-Effort" traffic ("BE").
• During the time that a subscriber's traffic is assigned the lower priority status, such traffic will not be delayed so long as the network segment is not actually congested. If, however, the network segment becomes congested, such traffic could be delayed.
• Given our experience so far, we have determined that a starting point for the upstream Port Utilization Threshold should be 70 percent and the downstream Port Utilization Threshold should be 80 percent. (The term "port" as used here generally contemplates single channels on a CMTS, but these statements will apply to virtual channels, also known as "bonded groups," in a DOCSIS 3.0 environment.) -- (Basically, a "port" is the neighborhood connection.)
• (Given the above) When a subscriber uses an average of 70 percent or more of his or her (individually) provisioned upstream or downstream bandwidth over a particular 15-minute period, that user will be in an Extended High Consumption State.

Simply put, there are four steps to determining whether the traffic associated with a particular cable modem is designated as PBE or BE:

1. Determine if the CMTS port is in a Near Congestion State.
2. If yes, determine whether any users are in an Extended High Consumption State.
3. If yes, change those users' traffic to BE from PBE. If the answer at either step one or step two is no, no action is taken.
4. If a user's traffic has been designated BE, check user consumption at next interval. If user consumption has declined below predetermined threshold, reassign the user's traffic as PBE. If not, recheck at next interval

Re:How do you put up with yours?

[LordKazan]

that's YOU. that's not why we as a country don't have it this way.

btw: we already have government standards on what can be legally called broadband. they're quite clear, and completely apolitical (beyond being unreasonably low.. pretty much everthing DSL or cable qualifies)

Re:Actually, its not...

[Jah-Wren Ryel]

Good video over the net is 2 Mbps for Netflix.

MAYBE that's true for netflix. It isn't true for other services.

I'm looking at season 1 of "Parks and Recreation" from Itunes at 720p.
The bitrate of these episodes is roughly 4.5Mbps and it is just at the bare minimum of what I consider acceptable. They are going to need to more than double that for good quality 1080p, say at least 13Mbps for broadcast-quality (not blu-ray) 1080p. For example, NBC's nationwide 1080i backhaul is 15Mbps h264 and they are the lowest bitrate of all the major networks, ABC is roughly 35Mbps h264 for their 720p backhaul.

So, 13Mbps for decent 1080p material - that works out to:
~4.0GB at good 1080p
~1.5GB at itunes quality 720p
for typical 42 minute show with no commercials.

That puts comcast's cap at about 2 hours a day for good 1080p or 5.5 hours at itunes quality.
For an entire family, with no commercials.

The average television is on for more than 8 hours a day in the US.

That puts comcast's 250GB cap at about half of the necessary level for itunes quality television, and a quarter for good quality 1080p. For the AVERAGE family. It doesn't account for the bell-curve at all. The cap needs to be more like 2TB to cover the average household video consumption out to the 1st standard deviation.

Re:Laws

[T-Bone-T]

The electric company isn't always a monopoly. In Texas, the electric company can't own lines or power generation equipment. They buy electricity wholesale and sell it retail. The Transmission and Distribution Service Provider is a natural monopoly, however. This means that your choice of electric company can be boiled down to what sources your electricity comes from.