Comcast Users

[VOIPoTim]

For those of you specifically with Comcast, have you had any problems with not being able to connect?

When this happens, the red light on the front of your adapter would be flashing red.

[N9MD]

Funny you should ask. I was in my Boca Raton residence over the Xmas-NewYear break. While there I opened a new Comcast broadband account. Using my PAP2T-NA adapter, I experienced some curious results in attempting to register a variety of VoIP providers --- all of which work on the PAP2T-NAs in my New Jersey locations, indicating that my registration data is correctly inputted.

I refer to the Registration State on the Info page.

VOIPo - Offline

AxVoice - Offline

Free/Talk/CallDigits - Offline

FreeWorldDialUp - Offline

ViaTalk - Offline

GizmoProject - Online

StanaPhone - Online

CallCentric - Online

When I purposely enter an incorrect password for each of the "Offline" providers, the Registration State message changes to "Can't connect to login server".

I always use SIP Port 5060 for Line 1 and 5061 for Line 2. But changing to other SIP ports within the 5050 to 5099 range gave similar results.

All of this would seem to indicate that my PAP2T is reaching the Comcast server -- via my LinkSys WRT54G Router and the Comcast CableModem -- but the Line 1 and Line 2 lights are out for the "Offline" providers and glow brightly with the "Online" ones. The Power and Internet lights are on --- with no red lights.

So, is Comcast blocking ports? How could that be if some providers are useable on Port 5060 and others are not?

[Unfortunately, I am back and forth between NJ & FL so I can't always do "in-depth" experimenting with the VoIP stuff when I'm in FL. Mainly, because the 80 degree blue sky "winter" weather makes my wife force me onto the golf course daily.]

[VOIPoTim]

So, is Comcast blocking ports? How could that be if some providers are useable on Port 5060 and others are not?

[Unfortunately, I am back and forth between NJ & FL so I can't always do "in-depth" experimenting with the VoIP stuff when I'm in FL. Mainly, because the 80 degree blue sky "winter" weather makes my wife force me onto the golf course daily.]

We don't think that Comcast is block ports per say, but it's obvious that they are playing with traffic and this seems to be causing some intermittent problems. We have a workaround to avoid this, but I want to get some more stats on how many people see random issues with them.

For once, I actually agree with Brendan on something.

[Montano]

I have Comcast here in CA. and I can't say that I've noticed any issues. I have several providers on my various TA's and they are all functioning normally.

Speaking of Brendan.... did he thank you for the gift basket ??

[VOIPoTim]

Speaking of Brendan.... did he thank you for the gift basket ??

Of course not. We haven't exactly been on speaking terms for the last year or so, but I haven't missed his bday or holidays.

[Brian]

No issues w/VOIPo yet, but I did have some issues with VT a few weeks ago, had to adjust my port range.

[N9MD]

I have Comcast here in CA. and I can't say that I've noticed any issues.

The Comcast problems have mostly been reported in the SouthEast -- rather frequently in Florida. Rather than flagrantly blocking ports, they may simply be "modifying" TCP/RTP packets (whatever that means) which effectively prevents successful functioning of VoIP adapters -- even though, as my prior post indicated, I apparently can register my PAP2 with Comcast but get an "offline" indication (as opposed to "cannont register").

I'll be back in Boca Raton next week and I plan to research the issue with Comcast. (Read that as "I intend to rip them a new one.")

[VOIPoTim]

The Comcast problems have mostly been reported in the SouthEast -- rather frequently in Florida. Rather than flagrantly blocking ports, they may simply be "modifying" TCP/RTP packets (whatever that means) which effectively prevents successful functioning of VoIP adapters -- even though, as my prior post indicated, I apparently can register my PAP2 with Comcast but get an "offline" indication (as opposed to "cannont register").

I'll be back in Boca Raton next week and I plan to research the issue with Comcast. (Read that as "I intend to rip them a new one.")

Here is an example of what we're seeing. We'll get the registration request from an ATA, but they strip the login info from it or we'll get a registration request with it redirecting media traffic to another server we don't own.

Not all the time, just basically every time I've had a Comcast problem, it's been one of those. Then later in the day it just starts working again. Side-by-side on DSL, the DSL would have no issues. It's like they are reconstructing the packets and not getting it quite right.

[dswartz]

Tim, I wonder if this is an artifact of the sandvine traffic shaping crap comcast is doing? If this is some sort of proxy functionality, maybe (as you wonder) they are screwing up other protocols?

[VOIPoTim]

Tim, I wonder if this is an artifact of the sandvine traffic shaping crap comcast is doing? If this is some sort of proxy functionality, maybe (as you wonder) they are screwing up other protocols?

I think it's probably related, yeah.