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Comcast Accused of Blocking VoIP 325

kamikaze-Tech writes "Comcast, the largest USA Broadband provider is being accused of VoIP blocking, just days before they release their own VoIP offering. According to a long standing thread on the Vonage Forums, many Comcast ISP users are unable to use Vonage. Tempers are flaring: 'Although you will see all manner of opinions on this thread, there seems to be a sentiment that - politely put - Comcast could really be doing a better job of carrying Vonage bits.' Looks as though this could be the beginning of the broadband quality wars, with Comcast taking the first step."
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Comcast Accused of Blocking VoIP

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  • Actually... (Score:2, Informative)

    by Xystance ( 660413 ) <my AT xystance DOT org> on Thursday March 02, 2006 @10:33AM (#14834361) Homepage
    The last few days I've been having real problems with OUTGOING Vonage calls, but incoming Vonage calls have been ok.

    Outgoing calls are extremely choppy and cutout in the middle of words, but I can hear the other person without a problem.
  • Not enough upload (Score:3, Informative)

    by DrRobert ( 179090 ) * <rgbuice@[ ].com ['mac' in gap]> on Thursday March 02, 2006 @10:38AM (#14834400) Homepage
    I had Comcast and Vonage. Comcast's lower lever service has a limited upload cap which is not quite enough to get consistently clear calls, especially if you are doing anything else with the computer at the same time. It is not clear that this is a problem because they don't talk about upload bandwidth on the Vonage box, only total bandwidth, which Comcast technically meets. I cancelled Vonage after a couple of months, when I encountered almost comical ass-ness from the Vonage customer support. Those guys are complete bastards.
  • by Buffo ( 773488 ) on Thursday March 02, 2006 @10:40AM (#14834413) Homepage
    >>I eagerly await the broadband over power lines initiative


    There are serious issues with BPL. It generates interference that compromises several amateur radio bands, and is likewise interfered with by the legal operation of numerous low-power transmitters. (This includes CB radio transmitters as well as ham radio transmitters.)

    Visit for more information.
  • by garcia ( 6573 ) on Thursday March 02, 2006 @11:23AM (#14834723)
    Anyone care to take a guess on how long I'd be able to keep that up before they shut me down?

    Anywhere from a few minutes to 24 hours. The uncapped modems were usually scanned for at least twice daily. First "offense" and your modem was cycled remotely and the correct cfg file was downloaded again "capping" your modem. Your account was flagged and a ticket was opened for you. If you did it again then you were booted permanently for a TOS violation. Depending on the severity of the uncapping (10+mbit/10+mbit) you might be banned on the first violation.

    Some people were referred to legal services after their first offense and ATTBI was looking to prosecute for theft of service.

    Not a good idea, really.
  • by XorNand ( 517466 ) * on Thursday March 02, 2006 @12:23PM (#14835270)
    FYI, SIP is only the signaling protocol. Voice traffic is carried via RTP and RTP ports are dynamically allocated. There is also already significant development underway to improve the security of both SIP and RTP. See SIPS (SIP Secure).
  • Not Surprising (Score:2, Informative)

    by RebrandSoftware ( 817021 ) on Thursday March 02, 2006 @12:38PM (#14835403) Homepage
    I've been fighting comcast's and other ISP's blocked ports for a few years now: []

    Check out the visitor-submitted "Complaint List by ISP" at the bottom of the page, Comcast has the longest list of all.
  • by Anonymous Coward on Thursday March 02, 2006 @02:36PM (#14836489)
    I have had Comcast for years and Vonage for about 8 months. I've never had a problem. I had to put a little QualityOfService stuff on my OpenWRT router so I could talk reliably while eMuleing, but...

    I dunno what anyone is talking about. I love my Comcast connection. I do pay $10 extra a month to get the 8mbit/768kbit service, but it worked fine before that - I only upgraded cuz I was able to expense it off to my employer and figured "why not?".

    I am not astroturfing! I could not ask for a better broadband connection!

    (I have been on my Vonage phone for at least 10 hours over the last 3 days - no blocking here)
  • just one data point (Score:2, Informative)

    by marvinglenn ( 195135 ) on Thursday March 02, 2006 @05:15PM (#14837837)
    For what it's worth... I have a customer (of my support business) on Comcast connected to me via a VPN who I sometimes call on a SIP phone over that VPN connection, and I haven't had a problem yet. I have the phone codecs set to G723, which has a bandwidth of 6.3kbs (or 5.3kbs selectable).

    Just one little data point.

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