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Networking Communications

Comcast's Congestion Catch-22 177

Posted by Soulskill
from the solution-looking-for-a-problem dept.
An anonymous reader sends us to Telephony Online for a story about Comcast's second attempt at traffic management (free registration may be required). After the heavy criticism they received from customers and the FCC about their first system, they've adopted a more even-handed "protocol agnostic" approach. Nevertheless, they're once again under scrutiny from the FCC, this time for the way their system interacts with VOIP traffic. By ignoring specific protocols, the occasional bandwidth limits on high-usage customers interferes with those customers' VOIP, yet Comcast's own Digital Voice is unaffected. Quoting: "The shocking thing is just how big a Pandora's box the FCC has appeared to open — and it just keeps getting bigger. When the FCC first started addressing bandwidth usage and DPI issues, it quickly found itself up to its knees in network management minutia. Not long after that, it followed another logical path of the DPI question and asked service providers and Web companies about their use of DPI for behavioral targeting. Now it seemingly has opened up huge questions about what it means to be a voice carrier in the age of IP. It's not hard to imagine the next step: What about video? Telco IPTV services are delivered in roughly the same way as carrier VoIP services — via packets running on the same physical network but a prioritized logical signaling stream. Is that fair to over-the-top video service providers?"
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Comcast's Congestion Catch-22

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  • Congestion? (Score:5, Insightful)

    by Mooga (789849) on Saturday January 24, 2009 @12:21PM (#26589315)
    If Comcast is having major network congestion then why did they automatically double everyone's download speeds? I got a letter a few days ago saying that I now get 12 down rather then 6. Seems like a BAD idea if they are having congestion issues...
    • Re:Congestion? (Score:5, Interesting)

      by WhatAmIDoingHere (742870) <sexwithanimals@gmail.com> on Saturday January 24, 2009 @12:23PM (#26589331) Homepage
      Their issue is upload not download.
      • Re: (Score:2, Insightful)

        by stim (732091)
        Yeah because they buy non symmetrical DS3's and above amirite?
        • Re:Congestion? (Score:5, Insightful)

          by timeOday (582209) on Saturday January 24, 2009 @12:36PM (#26589479)

          Yeah because they buy non symmetrical DS3's and above amirite?

          I doubt the problem is up at that level anyways. The price per byte on the backbone is so cheap it hardly matters. It's the few miles nearest end users - where most of the network actually is - that matters.

          I wish they (all ISPs) would start honoring TOS flags and then start selling packages like X gigabytes of 1st class traffice, Y gigabytes of 2nd class traffic, and Z gigabytes of 3rd class traffic. Presumably people would use 1st for VOIP, 2nd for ssh or websurfing, and 3rd for bittorrent. But if somebody configures bittorrent to use 1st class, it's not the ISPs problem.

          All that said, I have comcast's very slowest "broadband" - 768kbps (i.e. under 1 mbit), and vonage always works fine. I haven't noticed any congestion problems on their network.

          Finally, why the submitter thinks video is such a dilemma is a bit of a mystery to me. 99.9% of video is download - not interactive video phones and such - so having some jitter isn't really a problem, easily solved with buffering. It doesn't need to compete on the millisecond scale with voice traffic.

          • Re: (Score:2, Interesting)

            The problem is that ISP's pay per megabyte for uploads. Downloads are free for them except for the cost of the line and equipment maintenance., etc. That's what this is really all about.

            • Re:Congestion? (Score:5, Informative)

              by drinkypoo (153816) <martin.espinoza@gmail.com> on Saturday January 24, 2009 @12:59PM (#26589693) Homepage Journal

              The problem is that the DOCSIS spec involves having your own little slice of frequency for downstream but everyone shares upstream. Your DOCSIS 1 stuff would let you dump 5 or 6 megabits to each of thousands (well, okay, maybe hundreds) :) of subscribers at once if you could actually feed the data into your head end fast enough. But sending the data back upstream is done on a shared frequency. Some line cards have multiple frequencies (no idea what they are now; when I worked for Cisco Santa Cruz when they were developing the Cisco DOCSIS modem ref design firmware it was the MC11 and MC16, I think, the MC16 had six upstream channels) so that you could send the same downstream to a whole bunch of places, but segment their upstream and feed it into the different upstreams (inputs on the line card.) If you run out of bandwidth you can charge more, and buy more bandwidth. But if you run out of upstream bandwidth on the line card, you have to add a line card and go forth and physically segment your network.

              • Re:Congestion? (Score:5, Informative)

                by grumling (94709) on Saturday January 24, 2009 @02:09PM (#26590339) Homepage

                You don't understand cable system design. The reason for the 6:1 ratio between upstream and downstream is not because Cisco (or anyone else) thinks you can oversubscribe the upstream spectrum, but because upstream carrier to noise ratios are much worse than downstream. Because of the lower CNR, upstream modulation has to have a lot more interleaving and error correction (and much lower symbol rates). It also helps isolate noise problems to a smaller service area.

                Part of DOCSIS 3 spec is 64QAM upstream. Some operators are trying it now, and finding out that there's a whole new level of plant maintenance necessary to deliver a good upstream bit error rate. Meanwhile, the normal downstream carrier is 256QAM (6.4MSym/s symbol rate), which requires a 3dB improvement in CNR over 64QAM at the same symbol rate. As fiber is driven deeper into the cable network it will be much easier to increase the upstream modulation to 256QAM and downstream modulation at 1024QAM. Typical cable systems today use 16QAM modulation in the upstream, with a 3.2 MSym/s symbol rate.

                And, it is fairly common to have multiple upstream carriers in a node (neighborhood). DOCSIS 3.0 adds support multiple downstream carriers* through devices called edge QAMS. The downside of that is most operators have 65 or so analog channels, several dozen digital cable channels, 4-5 VOD carriers, and one DOCSIS 2.0 carriers in the downstream. The push is to get rid of the analog channels, but that's politically unpopular since it would require all customers to get a set top box for every TV (someday tru-2-way TVs and set top boxes will be at Best Buy, but it's a long time coming). Once 3.0 is deployed, the typical system may have 3 or more bonded downstream carriers/service group, about 500 customers. End users will need a new modem to get full use of the channel bonding, but it should be worth it for the much greater increase in speed.

                Finally, everyone always gets the "shared bandwidth" argument wrong. Most people think of DOCSIS like classic Ethernet, with a hub or daisy chain cable. This means that Ethernet NICs need to use CSMA/CA to avoid collisions. There is no way for a cable modem to hear another one, so the CMTS assigns a mini-slot to a cable modem when it is provisioned/registered (which essentially makes a TDMA channel). the ONLY time a modem is permitted to transmit is at it's assigned mini-slot. Over the years, CMTS software has improved, and operator's understanding of the configuration has become much more granular, to the point that bandwidth optimization is much better understood than it was 10 years ago, along with moving from 7200 series network engines to VXR and above (in the case of Cisco).

                *There is some use of multiple downstreams now, it has been in the spec since DOCSIS 1.1, but isn't needed on much more than a temporary basis. Individual modems can only tune one carrier at at time, so it is typically used to get more customers on a node than it is used to get higher speeds. However, some operators have used multiple downstreams to isolate business class customers from everyone else.

                • by drinkypoo (153816)

                  You don't understand cable system design. The reason for the 6:1 ratio between upstream and downstream is not because Cisco (or anyone else) thinks you can oversubscribe the upstream spectrum, but because upstream carrier to noise ratios are much worse than downstream.

                  You don't understand English. I didn't say that at all. I said that you have less upstream. I didn't say why. Nice try though. I will grant that you probably know much more about DOCSIS than I do, though. My point still stands, since I didn't say what you thought I said, but something true instead.

                  What I said is that the upstream is oversubscribed. There is more demand than supply; furthermore, they sold to the demand, without increasing the actual supply. That's called oversubscription.

                  Over the years, CMTS software has improved, and operator's understanding of the configuration has become much more granular, to the point that bandwidth optimization is much better understood than it was 10 years ago, along with moving from 7200 series network engines to VXR and above (in the case of Cisco).

                  This in no way chang

                • by afidel (530433)
                  Slightly off topic but tru-2-way SUCKS, who the hell thought it was a great idea to have the cable companies software running on MY hardware? Why couldn't they just make an open standard like every other telecommunications network in the world since the old Ma Bell was forced to open up? Oh yeah, the same reason they run completely crappy software to begin with, they don't give a crap about the customer because they don't have to.
            • Re: (Score:3, Informative)

              by jo42 (227475)

              The problem is that ISP's pay per megabyte for uploads. Downloads are free for them except for the cost of the line and equipment maintenance., etc.

              Horse crap. ISPs pay the same for bandwidth usage up or down.

              • by Retric (704075)

                Not the big guy's. http://en.wikipedia.org/wiki/Tier_1_network [wikipedia.org] I think Comcast is a Tier 2 and pays for some, but not all of their traffic.

                As a result, the term Tier 1 Network is used in the industry to mean a network with no overt settlements. An overt settlement would be a monetary charge for the amount, direction, or type of traffic sent between networks.

                Common definitions of Tier 2 and Tier 3 networks:

                * Tier 2 - A network that peers with some networks, but still purchases

          • Re:Congestion? (Score:4, Insightful)

            by SanityInAnarchy (655584) <ninja@slaphack.com> on Saturday January 24, 2009 @01:04PM (#26589743) Journal

            start selling packages like X gigabytes of 1st class traffice, Y gigabytes of 2nd class traffic, and Z gigabytes of 3rd class traffic.

            That seems like it would be a bit complex, and also problematic if they did not ship their own routers and instructions for configuring it.

            Why not just sell pure bandwidth, and if people want to prioritize things, let them do it within their own networks? If I'm saturating my connection with BitTorrent, it's really up to me to QoS it down until Skype works. But, if I'm saturating my connection with BitTorrent, and someone else is having problems with Skype, that suggests they should buy more bandwidth.

            I can see where TOS might be easier for the ISPs, let them squeeze a bit more out of their networks, maybe oversell a bit more and acknowledge that your torrent will slow to a crawl (but your voice will still work) during "peak" hours.

            On the other hand, Amazon seems to be able to put a relatively cheap, relatively constant price on all network traffic to Amazon Web Services. I don't know if my bill is typical, but I pay $65 for fiber -- split evenly, that would be 300 gigs upload and 176 gigs download, or 150 gigs up and 265 gigs down... per month. I mean, I might do more than that torrenting, but not much, and I imagine that's a good deal more than Comcast currently provides.

            • by PopeRatzo (965947) *

              Why not just sell pure bandwidth

              Because the telecoms want to control the supply, and because most of them also have huge investments in the production of content.

              That's why the biggest ISPs all have their own branded browsers. They want to hook customers into the notion that the internet is just like TV, you take what you're given.

              • I should rephrase that, then.

                Why aren't there more ISPs who just sell pure bandwidth?

                My biggest complaint about my current ISP is the bundling -- there is actually no way to just get Internet, it's Internet + Phone, or Interent + TV, or all three. However, it's also $65 for 100 mbit fiber, no installation fee, and in my experience, no throttling, no bullshit.

                I don't really care for the ToS, so I suppose if they do start sucking, there won't be a lot I can do about it. But so far, they've been good.

                So my que

                • by droopycom (470921)

                  Because people dont want to pay $65 but $35 or $45 ? And because they already have Phone or Cable TV anyway ? Or because the fiber guy is not going to pull its fiber to their neighborhood ?

                  Seriously, if I could get $65 fiber, I might, but where do I need to live ?

                  • If you've already got cable, it seems to me that getting TV with your fiber could still be an attractive offer. The $65 is the cheapest plan, but that's phone+internet, no TV.

                    Seriously, if I could get $65 fiber, I might, but where do I need to live ?

                    Fairfield, Iowa. [liscofiber.com]

                    If a town of 10k people, in the middle of nowhere, can get that -- or crappy DSL, or sort of decent cable, and there's another, business-oriented ISP around selling fiber, too -- why is Comcast winning everywhere else?

                    • because it is easier to get right of way for the fiber, and you don't inconvenience everyone and their brother by having to rip up street or sidewalks and cause traffic jams in fairfield iowa than it is in say, atlanta georgia?

                    • by Miseph (979059)

                      My guess is that Comcast didn't see your community as valuable enough to pursue until there was already strong competition. Their usual MO, at least around here, is to get towns to sign into contracts where all competition is stifled before it can get off of the ground and then providing the bare minimum service expected at the highest price tolerated in order to keep people from complaining and taking political or economic action against their coerced mediocrity.

                      In their defense, however, they could be a l

            • Re: (Score:2, Interesting)

              by stonefoz (901011)
              Perhaps it doesn't need three tiers, but two would still alleviate real times problems. No, you can't just do router magic tricks on the customers end line, nothing there will affect their incoming traffic, it has to be done at the ISP. X (a much smaller percentage) of realtime bandwidth, and Y (all the rest of it). Customers wouldn't have to configure shit, Skype, Broadvoice and YouTube, etc.. would have to mark TOS on they're outbound. Customers would only have to be informed if they've asked to too much
            • by sjames (1099)

              They don't want to do that because if they actually implemented fair queueing people would figure out that they don't provision anything even close to the promised bandwidth.

              Ideally, they would set up fair queueing and respect each customer's TOS flags within their slice. They would need to make sure that each slice was at least big enough to handle a VOIP call or two.

              The current method of claiming you can use all you want and then tossing anyone who 'overuses' back into dialup purgatory is simply not accep

          • by HangingChad (677530) on Saturday January 24, 2009 @01:38PM (#26590053) Homepage

            I doubt the problem is up at that level anyways.

            It's probably the NSA's traffic cloning and storage system that can't keep up with trying to record all of America's VOIP calls. We're sorry, but this mailbox...United States of America...is full.

          • I wish they (all ISPs) would start honoring TOS flags and then start selling packages like X gigabytes of 1st class traffice

            That's not how the TOS flags work. Bits 3-5 are the relevant ones:

            • bit 3 - Low Delay
            • bit 4 - High Throughput
            • bit 5 - High Reliability

            These are generally mutually exclusive. High Reliability is pretty much obsolete - no one cares about packet loss at the IP layer. The important ones are bits 3 and 4. For VoIP traffic you want low delay, but you don't care much about throughput - a mobile phone only uses 9.6Kb/s and no one complains much about voice quality there. For HTTP or SCP traffic you want hig

          • ISPs need to be held responsible for the bandwidth they sell! If they can't do it then they shouldn't advertise it.

            ISPs should NOT be allowed to legally prioritize any traffic. This does NOT exclude the ability for ME to prioritize my OWN traffic making it my responsibility and freedom.

            Now you network minded people will say: How do they know what traffic of yours is important to you when you and your neighbors peak above the base guaranteed rates they advertise?
            The solution is more simple than many of the s

        • by Detritus (11846)
          No, the problem is the design of the network. The uplink and downlink use completely different paths. The uplink path has limited capacity.
      • Re:Congestion? (Score:5, Insightful)

        by Sancho (17056) * on Saturday January 24, 2009 @01:02PM (#26589715) Homepage

        Is that why they instituted download caps?

      • For Voip, this issue is latency not throughput.

      • True that.

        When using P2P, on Comcast, I get beautiful download rates...until my upload goes above 200KB/S.

        When that happens my download rate is dropped, along with upload, down to under 10KB/s. Period.

        I've been able to sustain download rates of up to 1MB/s as long as my upload is maintained at LESS then 200KB/s. For the most part, it appears they are using your upload rate to determine your download rate. Needless to say, I keep my upload set to 190KB/s(even a SINGLE spike over 200KB/s triggers the drop).

        I'

    • Re: (Score:2, Funny)

      by stim (732091)
      Step 1) double every users available bandwidth Step 2) charge by the meg Step 3) PROFIT!
    • by b4upoo (166390)

      Comcast is having big issues in my area. The initial time to hook up to my ISP every day is between three and five minutes. That is lousy service.
      Now that they are providing phone service on the same cable lines if they cause a death due to net congestion or not being able to hook up to their service then huge damages as well as punitive damages should apply.
      I don't give a hoot if they have to run two cables into every home this no

    • by kimvette (919543)

      According to speedtest.net, using the Portland, Maine server I am getting 19,295 kbps down and 6,479kbps up. Not too shabby! That's like having 12 bonded T1 lines' worth of downstream bandwidth, or nearly half a T3's worth.

      However they are selling this bandwidth to me, I am agreeing to purchase it, who are they to tell me that if I approach or exceed 70% of what they agreed to sell me and I agreed to purchase that I am using too much of it, should I decide to do so? We have a contract: they offer bandwidth

  • by paintballer1087 (910920) <paintballer1087&gmail,com> on Saturday January 24, 2009 @12:22PM (#26589329)
    It would have been first, but someone was on the phone.
  • by nweaver (113078) on Saturday January 24, 2009 @12:28PM (#26589383) Homepage

    If someone is doing very high traffic, enough to get into Comcast's temporary "QOS Low" category, they are probably sending and full rate. If you are sending at full rate, the typical end-host NAT and buffering alone will cause bad quality for VoIP (search for VoIP and BitTorrent for a lot of such tales). There is nothing Comcast's network management really does to affect things in this case anyway.

    Comcast's network management should only cause additional VoIP issues when the big transfer STOPS and the VoIP call is made within only a few minutes (before the user's link is reclassed back into the "QoS normal" category).

    • by Sancho (17056) * on Saturday January 24, 2009 @01:01PM (#26589703) Homepage

      Did you read the part in the summary which said that Comcast VOIP was unaffected by this problem?

      • by Jah-Wren Ryel (80510) on Saturday January 24, 2009 @01:53PM (#26590219)

        Did you read the part in the summary which said that Comcast VOIP was unaffected by this problem?

        What was not mentioned is that Comcast's VOIP is out of band. I'm no comcast apologist (comcast's policies were the straw that broke the came'ls back and got me to move to a new house where I could get verizon FIOS) but this is less of an issue that it has been made out to be. From day one, comcast's VOIP has used seperate channels from their internet services. Their VOIP is limited to connecting to POTS or other comcast VOIP customers. It is not on the internet, it is only on a comcast private intranet.

        • Re: (Score:3, Interesting)

          by nine-times (778537)

          From day one, comcast's VOIP has used seperate channels from their internet services.

          I'm not sure that's really the issue. I'll admit a little bit of ignorance on the issue, but what would happen to your upload rates if Comcast opened those VOIP channels to normal data? Or what if they allowed VOIP to travel on those channels whether they were the VOIP provider or not?

          Because I think the issue is that they're providing a limited amount of bandwidth to the home and complaining about congestion, meanwhile setting aside access for their own services. I can't blame them, since it probably m

          • I'm not sure that's really the issue. I'll admit a little bit of ignorance on the issue, but what would happen to your upload rates if Comcast opened those VOIP channels to normal data? Or what if they allowed VOIP to travel on those channels whether they were the VOIP provider or not?

            The same thing that would happen if they opened their digital televisions channels to "normal data."

          • by isdnip (49656) on Saturday January 24, 2009 @05:15PM (#26592251)

            To clarify... Comcast Digital Voice, like any PacketCable service, uses reserved capacity. It comes off of the cable modem channel, at the physical layer (minislots), and it keeps the telephone calls off of the Internet. CDV is NOT an Internet phone service at all. It's a separate access network, using MGCP-derived signaling and RTP/IP encapsulation of voice.

            If the phone is not in use, then a tiny bit more capacity on the cable (100 kbps/call) is made available for data. If you think that's unfair, fine, but that's how PacketCable works, and it maximizes efficiency for the whole system. It's safe, legal, and non-fattening.

    • by Mooga (789849)
      My home router actually had a 10Mbps Half Duplex WAN port for some odd reason. I had to find a new router to get the full 12 down speed they promised. Oddly 10 Mbps WAN ports are still very common on home routers, even brand new ones.
      • That's really really weird because the design the WRT54G used, that I'd think would be something of the model other implementations are based on, didn't even need a second ethernet adapter. In that design the WAN and LAN ports are just different VLANs on the same 10/100 switch.
    • by TubeSteak (669689)

      If someone is doing very high traffic, enough to get into Comcast's temporary "QOS Low" category, they are probably sending and full rate. If you are sending at full rate, the typical end-host NAT and buffering alone will cause bad quality for VoIP (search for VoIP and BitTorrent for a lot of such tales). There is nothing Comcast's network management really does to affect things in this case anyway.

      Ummm no. Next time, instead of making up a hypothetical situation that relieves comcast of all responsibility, try finding out the facts.

      When the local loop is over 80% download or 70% upload utilization, Comcast's system drops you down to a lower priority if you're over 70% utilization (in the congested direction) for 15 minutes.

      You regain your priority once you've dropped below 50% utilization for 15 minutes.

  • I don't know what's going on in my area, but Comcast sucks ass out here. The connection will just flat-out drop for 10-20 seconds at a time. Really fucks you up when you're trying to play a game online. They've had techs out here a few times with no results. Thank God I just found out that Qwest has their 7Mbps DSL service out here. I'm crossing my fingers and hoping that it's better than fucking Commiecast's godawful service.
    • Re: (Score:3, Informative)

      by Detritus (11846)
      Sometimes you have to keep on complaining. I had a similar problem that wasn't solved until they finally sent out a team of real technicians with a spectrum analyser. Even then, it took them several visits to locate the faulty equipment that was generating interference on the local cable distribution system.
      • I could do that. Or I could save a few bucks and try Qwest DSL. I'll take the one that doesn't require endless complaints and hope for the best.
        • I just finished the switch from Comcast to Qwest (20Mbps DSL went live last Friday, dropped modem off at Comcast this morning). I too have had short, random disconnects with Comcast, annoying when gaming or VPN'd to the office. I had daily disconnects at 10:30am, modem wouldn't lose sync, but I would have 100% packet loss for 20-25 minutes. The connection was also weather-sensitive - during the last two extreme cold snaps here in Minneapolis, the connection was essentially useless.

          Qwest was a snap - plac

  • by Dyinobal (1427207) on Saturday January 24, 2009 @12:29PM (#26589395)
    Why do ISPs insist on being more than just a pipe? It's so dumb no one wants them to be anything else. Do they just not feel useful when they are a pipe?
    • by Frosty Piss (770223) on Saturday January 24, 2009 @12:38PM (#26589509)

      Why do ISPs insist on being more than just a pipe? It's so dumb no one wants them to be anything else. Do they just not feel useful when they are a pipe?

      Because there isn't a lot of profit growth in being "just a pipe", and like all businesses, they would like to make more money.

    • by ChromaticDragon (1034458) on Saturday January 24, 2009 @01:08PM (#26589785)

      Sadly with regards to Comcast, it's because they don't consider themselves primarily an ISP.

      It's not that they are an ISP and they want to be something else. It's that they are "SOMETHING ELSE" and DOCSIS came around and they looked and said "Hey. While we're at it we could charge folk a few extra bucks a month and give them Internet too." So it's very easy to understand how they wish to ensure you use THEM for your VoIP and video-on-demand needs.

      Seriously. Call their help line. Listen to their canned message while you're on hold. Does it say anything remotely close to "we want to be your ISP"? Nope. It says something like "we're happy to be your ENTERTAINMENT company".

      Nothing really surprises me anymore about their horribly pathetic reliability once you realize their idea of what they are.

      • by kimvette (919543)

        Seriously. Call their help line. Listen to their canned message while you're on hold. Does it say anything remotely close to "we want to be your ISP"? Nope. It says something like "we're happy to be your ENTERTAINMENT company".

        . . . which is exactly the reason for the download caps. They were perfectly happy to offer UNLIMITED Internet access (which I agreed to, so they are contractually obligated to provide if I had the money to blow on a good Boston attorney to push the matter) until online high-def becam

    • by Geof (153857) on Saturday January 24, 2009 @01:41PM (#26590095) Homepage

      Bandwidth is a commodity. As such is interchangeable: the provider of a commodity is in competition with everyone else providing the same commodity. They have to differentiate themselves based on price, which they can only do by cutting costs and increasing efficiency. Though market competition is in our best interests as consumers, it isn't in theirs. The last thing a company wants is for market competition to work efficiently to drive down their margins. That's why they will do everything they can to avoid selling a commodity: product differentiation, branding, and so on - strategies that effectively create mini monopolies (you don't buy an MP3 player, you buy an iPod; you don't buy shoes, you buy Nike).

      That's the main reason. Another, which applies especially to monopolies (hello telecoms!), is price discrimination. A company would like to charge each customer as much as that customer can afford to pay, but they don't want to lose business with a price that's too high. By developing different classes of service they can coax more money from those able to pay more. The classic example is first-class seating on flights. How much a customer is able to pay may also depend on how much the service is worth to them. It may not cost the telecom company any more to provide bandwidth for, say, VoIP users than for WoW players, but VoIP customers may be able to pay more because it saves them money elsewhere.

      It is the role of good market regulation to ensure competition works effectively to drive prices down towards costs. That is broadly good for consumers and for the economy as a whole. Companies - especially incumbent companies - should be expected to do everything in their power to fight to break the market. And they do.

  • 911 (Score:5, Funny)

    by WindowlessView (703773) on Saturday January 24, 2009 @12:29PM (#26589397)

    If you have VOIP, don't set your kitchen on fire during high congestion periods. Please people, a little take a little personal responsibility.

  • I don't know (Score:5, Insightful)

    by MindStalker (22827) <mindstalker.gmail@com> on Saturday January 24, 2009 @12:37PM (#26589499) Journal

    Why don't they just UPGRADE THE PIPES.
    My god every other first world country has huge bandwidth where these types of things aren't even a consideration. Yet comcast just whines because you can't run everything and be fair on tiny pipes.

    • by Anonymous Coward

      because they want to milk the current technology and still profit from it as long as they can. I know I work with these guys. No need for FTTH until there's competition.

      They'll just let the FTTH come in and then merge with that company or acquire them outright.

      the typical slogan of "they bought us" comes into play here. As cable becomes telco that's just what happens. Only you have to wait until the market forces make that happen. Here in NY Verizon basically takes about 10 thousand households away fro

    • Re:I don't know (Score:5, Informative)

      by drinkypoo (153816) <martin.espinoza@gmail.com> on Saturday January 24, 2009 @01:06PM (#26589767) Homepage Journal

      My god every other first world country has huge bandwidth where these types of things aren't even a consideration.

      Every other first world country has immensely higher population density. Canada's population is overwhelmingly located in certain centers and the remote population of Canada has just as much trouble as the remote population of the USA.

      This does not adequately explain why we don't have higher speed in the areas of extremely high population density, of course.

      We can solve these problems by forming community ISPs to wirelessly handle the last mile solution, which works in most places. Using solar-powered (or hell, wind-powered, it's very easy) mesh networks would work practically everywhere. IMO we would ideally replace the internet entirely with an alt-power mesh network. You can cross hills by putting a wind generator on top, running PoE as far as possible and putting PoE APs at each end of the wire. Wind generators can be made entirely out of junkyard parts (as can a welder to build it with, if you are crafty. a plastic fuel tank, some jumper cables, some scavenged wire and you've got a welder. The wind generator itself is made out of body metal, a steering knuckle, a wheel, an alternator. Easier to make with an oil drum instead of the body metal, though.

      The problem here is one of "meh". We have great ideas but never seem to execute. I put myself in this category.

      • You should know... (Score:5, Insightful)

        by AliasMarlowe (1042386) on Saturday January 24, 2009 @02:06PM (#26590319) Journal

        Every other first world country has immensely higher population density.

        Wrong, unless you're saying that Finland, Sweden, and Norway are not in the first world. http://en.wikipedia.org/wiki/List_of_countries_by_population_density [wikipedia.org]

        I live in Finland which has about 5 million persons at a population density of 15.6 per sq.km, while the US has about 300 million at 31 per sq.km, or double Finland's population density. Actually, about half of Finland's population is near the south coast (especially around Helsinki and Turku), while I'm in a rural area 300km north of Helsinki, so our regional population density is a bit lower. The largest town within 200km has about 80,000 people.

        I have fiber to the house with 100/10 service available. The service is eur55 per month, including IP TV. If it's possible in the countryside in Finland, then it should be possible in most of US, where local populations and population densities are higher.

        In fact, there are substantial areas of the U.S. with quite high population densities and local populations greater than all of Finland. Example: New Jersey, with 8 million persons at 438 per sq.km, and many millions more in adjacent areas. http://en.wikipedia.org/wiki/New_jersey [wikipedia.org]

        Your argument based on population density is a load of bollocks. You're just screwed by your ISPs.

        • Re: (Score:3, Informative)

          by drinkypoo (153816)

          In fact, there are substantial areas of the U.S. with quite high population densities and local populations greater than all of Finland.

          You don't calculate from the total area of the country. You calculate from the populated area. This is the same reason the comment below yours about Canada is wrong. Canadians are by and large clustered into population centers because most of their country is trees, rock, and snow. Americans are some of the most spread-out people in the "modern" world (all but attitude, anyway.) People are well spread out across the country, with a not that astoundingly high population.

          There ARE some sizable uninhabited reg

        • Except Finland, Sweden, and Norway are all small countries, with their own languages, that nobody else speaks.

          So it's very easy for Telestra or whoever, to just lay down fibre to all the 2,000 (for example) medium-sized (non-farming country) Swedish communities across the country. You've only got 2,000 to reach, they can spend the money and instead of selling cable, phone, and internet, they bundle it all into that 55 euro bill (jesus christ, like 75$? are there cheaper plans?!).

          When I was in sweden, althou

      • by ceoyoyo (59147)

        Yeah right. Funny, up here they give us exactly the opposite reason when telling us why our cell service costs so much.

        Canada's population density is around 3 people / km^2. US population density is around 30 people / km^2. Canada's urban population, as a percentage, is about 80%. The US? About 81%. (http://hdrstats.undp.org/indicators/41.html)

        So proportionally, Canada has about the same number of people living in cities but a LOT more space between those cities. Also, the people who do live in the co

    • by grumling (94709)

      Comcast rolls out DOCSIS 3.0 to 3 more cities:

      http://www.fiercetelecom.com/story/comcast-rolls-docsis-3-0-three-more-cities/2008-12-11 [fiercetelecom.com]

      And Denver, Salt Lake City, and most of the west coast should be done before the end of 2009.

    • So what you are suggesting is that a company that is bringing in 20% profit off one customer should voluntarily reduce that to 19% profit? have you no shame?

    • They're just waiting for the new and improved telco bailout 2009. The latest offering is a 6 billion high speed Internet grant [wsj.com] program. Why should comcast, or any big telco for that matter, spend money when the government will just give them handouts.

      These companies have experience with this. They have already gotten away with a 200 billion broadband scandal [pbs.org] without penalty for failure to deliver on their promises. Give crappy service and they get handed free money - what a great idea.

  • by Ant P. (974313) on Saturday January 24, 2009 @12:42PM (#26589545) Homepage

    The ISP supplying my workplace regularly blocks HTTP for up to hours at a time. Nothing else, just outgoing(!) port 80. First connections get dropped silently, then after a while it moves on to forged TCP reset packets when trying to connect to anything. Which is pretty worrying because they're the only ISP available here.

    • by GoRK (10018)

      Actually it sounds like they have a transparent web proxy that is malfunctioning. You can probably request that your traffic not be sent through the proxy.

      • by Ant P. (974313)

        I think the tech guys have had a few phone calls with them already about it. They keep pretending there's no problem on their end, which is bullshit because things like HTTPS work fine.

        I had bad DSL signal problems with my home line about a year ago, and it took literally months of phone calls before they sent someone out to verify that there was nothing wrong with my stuff. Funnily enough, the problem stopped the following week...

  • Not a "Catch-22" (Score:5, Insightful)

    by Lord Byron II (671689) on Saturday January 24, 2009 @12:49PM (#26589603)

    "Catch-22" implies a no-win situation. Comcast (and the other ISPs) have done this to themselves. They advertise unlimited Internet access (or make it seem like they're offering unlimited access) and then get upset when someone tries to use it.

    The ISPs should start advertising their download speed, upload speed, and bandwidth caps openly. Offer additional speed and bandwidth for a reasonable price. And if your infrastructure is such that sometimes you'll need to throttle someone, make it clear upfront how and when such throttling will happen.

    Right now, on Comcast's sale page, they only list the download speed of their connections. I couldn't find their upload speeds or the bandwidth caps (which I know to be 250GB). As far as I know, Comcast customers have no way to check to see if their being throttled or if they're near the bandwidth cap.

    It's really no surprise then that customers are upset.

    • by nurb432 (527695)

      "Catch-22" implies a no-win situation. Comcast (and the other ISPs) have done this to themselves. They advertise unlimited Internet access (or make it seem like they're offering unlimited access) and then get upset when someone tries to use it.

      It says unlimited here.. So don't think its a 'seems like'.... Its fraud.

    • by ceoyoyo (59147)

      Ah, you're forgetting something.

      When a company is faced with a choice between doing (a) and getting screwed, doing (b) and getting screwed or (c) not lying, it really is a catch-22. You see, if they do (c) then their customers realize that they're the ones who've been getting screwed the whole time.

  • Not agnostic (Score:5, Insightful)

    by Ghworg (177484) on Saturday January 24, 2009 @12:51PM (#26589615)

    If they are treating their own VOIP differently than other traffic then it isn't "protocol agnostic" at all.

    • Not that I would like to defend Comcast, but I do believe that most Cable phone service goes "out of band" and not over the internet. it uses a different frequency or channel on the cable than the internet connection. Kinda like DSL doesn't mean your phone is suddenly VOIP.

      • Re: (Score:3, Interesting)

        by Trekologer (86619)

        But Comcast does not. Comcast Digital Voice rides the same channel as cable modem. The only real difference between CDV and another VoIP product (ie Vonage, etc) is that the ATA is built into the cable modem.

        • by isdnip (49656)

          No, it uses the same modem but differently. PacketCable uses reserved cable capacity, separate from the Internet service. It does not touch the Internet. There is multiplexing in the physical layer to sort the services out.

          • by Trekologer (86619)

            A far, far majority of quality problems for both CDV and independant VoIP are cased by the connection between the end user's premesis equipment (eMTA) and the cable company's head end, inclusive of the neighborhood node: HFC plant signal quality or node congestion. It has absolutely nothing to do with the internet. Suggesting otherwise is just FUD.

    • by darkonc (47285)
      Yeah. It's protocol agnostic. It's provider pedantic.

      What they're blocking is VOIP through other phone providers -- whether they're using SIP or HTTP, they'd probably still block users of other providers, and pass any protocols that they're getting extra income for (again, no matter what the protocol used). . That's what makes them 'protocol agnostic'. You have to use your weasel words very carefully

  • DOCSIS? (Score:2, Informative)

    by Mathiasdm (803983)
    Comcast is a cable company, right? So isn't this just because their VoIP can be put in a separate Docsis channel (and prioritised accordingly), while 'regular' VoIP is sent as normal data?
  • by N7DR (536428) on Saturday January 24, 2009 @01:40PM (#26590079) Homepage

    I don't want to spend an hour writing a treatise on this, but I do think I need to make a few things clear.

    Several issues are convolved here, and the "right" answer to each individual issue is not obvious (at least not once one factors in political and business viewpoints), so the convolution is essentially a mess. Like the original poster of the story, I have to assume that the FCC decided intentionally to delve into the mess. Anyway, here are the real issues:

    1. There is (as far as I know) no new technology here. The PacketCable specs, which define how cable operators (most of them, anyway) implement VoIP were released in 1999. Comcast (like other US cable operators) has been deploying this technology since about 2002. As far as I know, the only part of the spec that Comcast don't really implement is the security portion. In any case, the specs are public and have been so for nearly a decade.

    2. There is a fundamental technical difference between over-the-top VoIP (i.e., service provided by a third party such as Vonage) and telephony provided by the cable company.

    3. The cable company can differentiate between its VoIP (or any other service needing preferential Quality of Service (QoS)) and ordinary so-called "best-effort" traffic, which is what is used to carry everything else, including over-the-top VoIP.

    4. The reason for this is that it is the only entity that has access to the Cable Modem Termination System (CMTS), which controls the microsecond-by-microsecond details of traffic flow over the plant between a customer and the cable operator's facilities.

    5. It is reasonable (from the cable operator's point of view) that since it owns the CMTS (and CMTSes are not cheap either to acquire or to manage), it's not voluntarily going to let some other company control any part of its operation (especially since if that gets screwed up, the customer experience is impacted).

    6. Looked at from the point of view of guarantees applied to services, this looks like a violation of net neutrality, since over-the-top operators have to fight for bandwidth against things like P2P and web browsing, while the cable operator's phone calls don't have to do so (they have QoS guarantees).

    7. But there is no law against violating new neutrality (as far as I know, in the US anyway). IANAL.

    8. One can also argue that although it *looks* like a violation of net neutrality, it is in fact not such a violation, since from the viewpoint of what is happening inside DOCSIS (the protocols used to manage bandwidth on the plant between the residence and the cable company), over-the-top VoIP looks completely different from the cable company's offering. From that technical viewpoint, they can be considered two different services, and hence it would (presumably) be fine even under net neutrality principles to treat them differently.

    Those are the basic ideas (although of course I've just summarized; it would take a lot more space to really describe all the details). But the basic point here is that there are lots of issues and viewpoints, some business-related, some political, and some technical. And much though one might like to demonize one party or the other, in this particular case the issues don't really seem to lend themselves to such a simple analysis.

    Disclaimer: this was a quickly-written post of my initial impressions given the rather sparse (and not unambiguous) information available.

    • by isdnip (49656)

      Good synopsis.

      On his last weekend before his resignation took effect, former FCC chairman Kevin Martin let off his final dump on Comcast, a personal battle he has waged his whole time at the FCC. He suggested that Comcast is disobeying a non-rule about an undefined concept called "network neutrality" that he never wants to apply to the big telephone companies.

      He knows that CDV is a PacketCable service, not on the Internet, so it is not really comparable. But at the bottom of the Notice is a question about

      • by hpa (7948)

        What it comes down to is that Comcast wants to pick and choose between two different rulesets. In particular, they want to provide an "information service" (a service at the other end of the Internet), while giving preferrential service using their cable plant to compete against telcos, without telco regulation.

        Sorry guys, you get to play one side or the other.

        • by Comen (321331)

          I agree somewhat with what you say on this, the politics here are crazy, and when you start talking about the government regulation It gets fuzzy for me.
          From a technical point of view I have to side with the Cable and Telco companies, for years they have been moving all their service to TCP/IP for many good reasons that make things more affordable and also easier to manage, this also opens up new services from combining the different services (caller id on the TV, Internet on TV etc)
          Moving all these service

  • VOIP!=Internet (Score:5, Informative)

    by not_anne (203907) on Saturday January 24, 2009 @01:44PM (#26590125)

    "Comcast Digital Voice uses Internet Protocol and not the Internet. Comcast Digital
    Voice calls travel on our private, managed network -- not over the public Internet. That makes
    it superior to other 'Best Effort' services delivering phone traffic over the public Internet."

    Source (emphasis mine): http://www.comcast.com/MediaLibrary/1/1/About/PressRoom/Documents/ProductsAndServices/digital_voice.pdf [comcast.com]

  • by nurb432 (527695) on Saturday January 24, 2009 @02:14PM (#26590379) Homepage Journal

    Well of course.

    If they offer a netflix alternative expect that to be a better performer due to shaping as well.

    Most people will just think the alternatives suck and choose comcast's service instead, never the wiser.

    • by funaho (42567)

      As has been mentioned earlier, Comcast VOIP is out-of-band. It's not that they're giving it priority; it's that it's not even part of the equation. It's just like how their current TV service is handled; your Internet being pegged doesn't stop your TV channels from working either.

      Now, if Comcast does start offering regular over-the-Internet video streaming, then yes I would agree it should be treated the same as anyone else's service.

  • Like nearly all cable systems, they still carry analog channels. Even if you have digital cable, channels 2 to about 60 are always analog. Thus, people with simple analog televisions can plug them into their cable and watch basic cable without a box.

    If they axed the analog channels and went with 100% digital that would free up about 300 mhz of bandwidth. That's enough bandwidth to add another 2000 megabits of capacity per subnode, which is a real lot. It would almost double their bandwidth in some
    • by langelgjm (860756)

      FYI, this is exactly what Comcast is planning on doing. The actual date of when they stop analog service will vary based on the market, but already in the Connecticut area, they're no longer signing up new customers for "standard" cable (i.e., 70 analog channels, no box).

      Of course, once everyone has a box, that's one less argument against a la carte pricing...

    • by isdnip (49656)

      No, the cable companies have been reducing the number of analog channels. RCN has completed "project crush", to get rid of them all. You thus need a cable box. Comcast still has some analog channels and the FCC has given them a hard time about removing them.

      But this has NOTHING to do with the issue at hand. That's downstream video capacity, unrelated to PacketCable, a separately-multiplexed two-way service that uses some of the cable's scarce upstream capacity. "Congestion" is not usually caused by scar

  • by Animats (122034) on Saturday January 24, 2009 @02:36PM (#26590597) Homepage

    We're still not doing congestion control very well. DOCSIS 3.0 [cablemodem.com], the new cable modem/hub standard, has many congestion management features, but they're a collection of features, not an integrated strategy.

    Realistically, there are two QoS options a congestion strategy for general IP-based networks can deliver:

    • Low latency, low bandwidth. This is what you want for VoIP and for the low-latency channel of games. For this to work, the network has to enforce the "low bandwidth" requirement by limiting the number of packets in flight. "Fair queueing" can do that on the network side. If you only have one packet in flight (i.e. you wait until each packet is delivered before sending the next one), you shouldn't see any packet loss. If you send more than that, you lose packets. TCP already plays well with fair queueing. UDP-based VoIP protocols that don't do adaptive congestion control need to be fixed.
    • High latency, high bandwidth For everything else.

    There are fancier reservation schemes, where you can reserve bandwidth, but they only work when all the players in the path cooperate, which tends not to happen. But there's no reason not to get the simple mechanisms above right.

  • Really. I mean that.

    Most VOIP uses UDP, which, *by specification* does not guarantee delivery timeliness, order, or that the packets will even arrive at their destination. It's strictly a fire and forget protocol, and this should have been understood from the outset. While I understand the advantages it brings on well-managed networks, and the value it has for those who can tolerate dropped speech and calls, it should not be thought of telephony, as it is nowhere near as reliable as conventional POTS n

  • For the past couple of days or so I was getting extreme latency on the network and I was like WTF is going on?

    So I took at the firewall's RRD graphs which tracks the traffic latency and it shows average 400ms. Spiked to 2002ms. I was like..WTF is this crap?

    I was gonna call them up and complain but figured some kids running bit-torrent and they will deal with em soon enough.

    Now this news got out I guess I still need to call and complain.

  • I have comcast, and I've noticed as of a few weeks ago that any HTTP download greater than 100 mb will simply die halfway through.

    newsgroup downloads will slow to 20kbs if the pieces are greater than 100 mb as well

    I use perhaps 20gb a month.

    Perhaps they wouldn't experience congestion if they UPGRADED THEIR INFRASTRUCTURE.

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