Comcast poisoning VOIP?

Wow - as we lead up to Freedom to Connect (F2C) in DC next month, isen warns us of something that really hits home as we all need to rally around the cause of Network Neutrality. Turns out there is a lot of anecdotal evidence that VOIP services such as Vonage and Skype are not working well for people with Comcast cable modem service. He points out that Comcast has their own POTS-over-cable phone service, so they would be particularly sensitive about competition.

As a subscriber to Comcast cable modem service AND their "digital phone" service, I can confirm the evidence on Skype. Up until a few months ago, my son was a regular Skype user, chatting with his friend as they played online games like Runescape, or just as they did homework. But then the quality went way downhill. Ironically, that meant that they would simply do the same thing on Comcast's digital phone service, which is a free local call, which effectively keeps us from using that service ourselves, for things like toll calls into the city or to family and friends elsewhere. It has allowed me to easily visualize a life without POTS at all - as it is, I haven't given out any number other than my mobile in at least a year, if not longer.

I tried to originate a Skype call a couple days ago, and it was painful, a sharp contrast to my experience six months ago.

As loyal Comcast customers over the past five years (for cable modem, for cable tv, and for four lines worth of POTS over cable) - I assure you it is a mistake to play with this kind of fire. I am happy to make my home available to any telco/network geeks out there who want to hook up some sort of monitoring or test gear to determine what if anything is being done to VOIP packets, and if, as I suspect, they are degrading VOIP service, I will lead the charge to go to the local government and get their franchise revoked...and take any other appropriate action to re-educate the folks at Comcast. I'm paying for a fat pipe to use as I want, and use it I shall.

And heaven help you if you get in the way of my ability to video iChat with my kids when I'm out of town.

Comments

[Ed Jewett]

Is this what causes my PC to crash when I'm Skyping?

[Andrew D. Brinn]

I've been using Skype for over a year for both computer to computer and computer to phone calls (SkypeOut). Recently we started having problems with our calls. The call begins to work fine, but the voice is cut off after about 1 minute of conversation. Disconnecting and reconnecting the call brings voice back, only to have it cut off again. My broadband provider is Comcast. From what I've been reading online I'm not the only one with this problem. If proven that Comcast is doing this on purpose I will have no choice but to cancel my services and connect via DSL. Truth is, my Comcast connection has NEVER delivered the promised access speed.

[Meredith Williams]

I've recorded long distance podcasts 2x in the past few months with no problem. But just this a.m., I had a podcast that went horribly. Conversation broke up intermittently and after about 20 minutes of talking, the person I was talking to could no longer hear me. It just cut off. I too am a Comcast user.

[C. W]

I too have been wacked by comcast, question is, can anything be done about them blocking voip services other than their own?

[Scott]

More anectdotal evidence here: I am in a comcast service area on a 2 month business engagement. I am a skype user, and normally deal with a different cable company in a different area (charter.net)
I never had this problem until I moved to comcast. The wierd thing is - the overall connection is great. That is, until I use a voip app. Then the skyp call dies out after about a minute and I usually even have to reset my router to restore my internet connection. I beleive that comcast is either poisoning voip packets or possibly doing something to poison the whole conneciton when they detect a voip packet. I have no idea if its legal or not - It sure as hell isnt winning me over to Comcast though I will tell you that.

[Bharat]

I use skype @ different locations. At home I have Comcast 4Mbps cable and at school we got 100Mbps line. And I use skype to talk to my family and friends in India where they have only 128-256kbps lines. At school, the audio quality of skype is top notch (better than or equal to phone), but at home, it is awfull. From home, voice is chopped or totally dropped. For me it looks like Comcast is clearly throttling Skype packets.

[Paul]

Skype isn't the only thing that has failed for me. I tried using a service called TeamSpeak, which is used primarily for talking while playing online games, and within a minute or two of being connected to one of it's servers my entire internet connection died. I thought it was just a fluke at first, but it happened three times in a row.

Neither Skype nor TeamSpeak had this problem until I moved and began using Comcast a few weeks ago.

[Mike]

Comcast surely is playing some wrong games here. I was using DSL earlier and never had these kinds of weird problems. The quality when using skype was not better and so I took broadband connection from comcast. After one hour of call on skype I lost my internet connection. It went totally dead.
I tried everything but it didn't work. I had to reboot my modem and router and tried everything but it didn't come up. After half an hour it came up on its own. I believe that comcast is doing some filtering somewhere which is below standards. If they dont stop this then they are going to lose loyal customers because these small things don't show good business ethics. Comcast should take a step ahead and pledge no to such practices. I believe someone reponsible will take this call and order a stop to such practices in such a big service provider.
Regards,
Mike

[Arul]

I am a comcast (now TimeWarner in my area) user. Just noticed something strange when skype starts... it connects to several comcast IPs (comcast dynamic allocation range) on random udp pots and evantually establishes a tcp connection on a ranom port on one of these comcast IPs... see the tcpdump and lsof listing below captured when skype is starting.

tcpdump window:
-------------------
tcpdump -i eth1

11:13:44.286640 IP xxxx.53948 > c-67-187-111-111.hsd1.tx.comcast.net.57041: UDP, length 18
11:13:44.286700 IP xxxx.53948 > c-67-186-204-251.hsd1.ut.comcast.net.15469: UDP, length 18
11:13:44.286738 IP xxxx.53948 > c-67-173-132-238.hsd1.il.comcast.net.4487: UDP, length 18
11:13:44.286779 IP xxxx.53948 > c-67-183-236-242.hsd1.wa.comcast.net.29923: UDP, length 18

lsof window: (notice skype is the process that made that connection)
--------------
lsof -i [email protected]:57041
COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME
skype 5220 xxxxx 19u IPv4 15504 TCP xxxx:48335->c-67-187-111-111.hsd1.tx.comcast.net:57041 (ESTABLISHED)

Anyone know what is going on?
Thanks.

[Phil Hoffman]

I've been a loyal Skype user for over a year. But my Adelphia cable service was bought by ISP and Skype immediately went from better than a "real" phone to absolutely unusable

[Bubba]

I have been using Skype now for about 18 months, I have a number of SkypeIn number and have paid for SkypeOut. When it was just Comcast cable and internet it was fine, now that my housemates signed up for the Comcast Triple-play the Skype has become unuseable. Connecting out isn't bad, the incoming packet-loss and jitter is considerable and I've had the Comcast service people out several times. I am going to try VPN'ing my Skype and see if this makes a difference.

[Claude Barnhart]

I used Skype with a headset for about a year, and signed up for the pay-per-year in January. I had been using Time-Warner/RoadRunner that was take over recently by Comcast. As in one of the previous messages, Comcast seems to be throttling Skype, as many times, using Skype knocks my Internet modem offline; and it will come back after closing Skype. I've tried this many times (closing Skype) and Internet service always comes back up. I smell something fishy!
--

Claude Barnhart, CP®
Certified Paralegal

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[TeamSpeak]

I have had trouble with Teamspeak and Comcast too.. makes me angry.

[bill]

I had such difficulty with Comcast I’ve had them come out and change out the cable to the house, change out connectors, over the past 8 months. The internet always seemed to go out at a critical time (mainly when I was on the phone via Skype) but never put 2 and 2 together. I recently had been logging when the internet goes down and have found it to be only when I am using Skype. I get the same as all others it seems…1 minute into call my internet goes down and I have to reboot my Linksys cable modem. As I make the call I see my access is denied in the modem status. I too have been in the IT industry for longer than I’d like to admit and I have seen this type of thing were a company will find a bug that causes a competing service to fail and this allows them to have deniability as they are not necessarily targeting a service just not fixing it on their side.

[Tim Mandeville]

I've had skype for about 8 months now using a LickSys ct200 and it has worked 100% =. Two days ago I placed 250$ worth of ads to sell our boat. I'm screwed since all the calls come in over my skype account and neither I or the party calling can transfer any info. Cell phone wa cut to 200 minutes an I've used up most of those.

Removed Skype and Linksys and de-fragged. Still a problem. Now what?

Would call Comcast but they will simply deny the problem I'm sure.

Used a broadband packet test. Speeds there are 100% so it is not comcast speed it seems, just the VoIP calls they may be mangling up.

Tim

[Michael]

Damn! That explains it!
Ive used Skype in/out for over a year and its been great. Back in May it suddenly went bad, the usual packet loss and disconnect. I suspected a conflicting IP but this certainly makes sense. I too use it as my main phone service. Comcast are *astards!

[anonymous]

Another Comcast Skype story: I use Skype in many locations on my laptop, flawlessly.

My Husband uses it on a computer at one particular location, and we thought the massive problems he had were due to the old headset on that computer. I brought my laptop to the same network, tried Skype, and ... it's crap. It's completely useless. Packet loss is incredible.

[RJ]

Something about cable. I run Teamspeak (better than Skype for gaming) on a computer with DSL and it works great. I take the same computer and connect to RoadRunner cable (TimeWarner took over Comcast) and Teamspeak doesn't even start to work. I have uninstalled Teamspeak and reinstalled it using RoadRunner cable and still nothing. I take the computer back to DSL and it works great. RoadRunner techs say that Teamspeak will work on their system and it is Teamspeak's fault. Hmmmmm. My friend just got Verizon's FIOS and it works super fast. I am wondering how the cable company can distinguish Voip from regular internet browsing.

[TheOldMan]

Hmm...there is a recurring theme here. My mother in MI has been using Skype for a few years to call her family in Europe daily. It was working great until Spring/Summer 07. I thought it was her new laptop with Vista however now I see that other people with Comcast are having problems. I'll investigate setting up a VPN to one of my office machines and see if that "fixes" the problem.

[Aaron]

I have been having massive problems with skype over the last 2 or 3 months. I have been with comcast since they took over att.net a number of years ago and had no complaints up til this March. All of a sudden skype has been disconnecting me constantly and many of my favorite online games have been super-laggy and/or I also get disconnected. I have a comcast tech coming out tomorrow despite the fact that the online tech-support chat guy said it wasn't comcast's fault despite all the evidence I gave. I'll wait and see what the technician says I guess but I am beginning to wonder if comcast is monkeying w/ skype traffic. I would switch to Verizon FIOS if I had the choice but I don't. I may still switch to high-end DSL if comcast refuses to fix this.

[Paul Tinsley]

I have recently been getting all sorts of issues using Skype and I use Comcast. I'm going to switch, because I keep reading many negative news reports about Comcast - they are just way too evil.

[Kimberly]

I too am a Comcast customer and am unable to use Skype. Have tried different head sets, microphones, just got a new computer (not because of Skype issue) and STILL can't use Skype. At least I know I am not loosing my mind or doing something wrong after hearing all of these complaints.

[Sanji]

I am also very upset with Comcast, will be disconnecting there service soon. I just ordered skype phone and I am getting no connection at all. The funny thing is, I called Comcast and the rep was helping me.. as soon as I said SKYPE he backed out and didn't assist any more. Right there I had doubt that there was something wrong between Comcast and Skype, well .. here we are...
Why don't they just match the price or something instead of blocking SKype... Just a jealous cable provider... We should all leave COMCAST and change to other internet provider..

[Nate Dog]

Just wanted to put my two cents in, I am a Comcast customer and use Skype extensively no problems. I am a business customer though... maybe that’s makes a difference?