iChat AV problems with Comcast

[deboni]

I've been a user of iChat AV for several years, and in the past 6-8 months it's stopped working as well as it used to. I routinely used it to connect from California to Florida and Indiana, and now I get about one minute or less of decent audio and video in a session before one or both ends starte breaking up and freezing. I've complained to Comcast about this, and have even sent them netstat info showing what seems to be peering problems between them and AT&T (large steps up in hop times across that boundary, in both directions). All they've done about it is send techs to change all the cables in my house, which is nice but does not fix the problem. I seem to have good bandwidth - 6 to 10 Mbit/sec - and other internet functions are fine, but video chatting is miserable (audio-only chatting still works ok). Can anyone advise me how to handle this? It makes iChat AV unusable for video.

Tom DeBoni
deboni@comcast.net

 

[wrldwzrd89]

It's clear to me from what you posted that the cause isn't on your end, so I'm not sure there's much you can do, other than bugging the technicians and explaining what you've discovered to them.

 

[deboni]

Thanks, wrldwzrd89, but I've already done that. What I need is advice from a networking engineer as to what specific information to gather so as to be convincing. I've done a lot of troubleshooting, and nothing I've provided Comcast has convinced them to escalate the problem beyond the local level. Some of their staffers have even claimed it's an Apple problem. Frankly, I'm about convinced they need to step in and provide some leverage to get it sorted out. iChat is a compellingly ingteresting and useful application, although probably not a simple one, under the GUI, and therefore it should be supported so it'll work for all of us. My setup is pretty vanilla: PowerBook, iSight, OS X 10.4.9, Airport Extreme base station, and Motorola Surfboard cable modem. I just need to know where to look, from this point in problem space.

Tom

 

[WildCowboy]

I was just at the SF flagship store yesterday, and there was a guy at the Genius Bar complaining about the exact same thing. (I'm pretty sure he had a MacBook, so I assume it wasn't you. )

The genius mentioned that it was a known issue and that it was a Comcast problem having to do with upload speeds. The user wasn't terribly thrilled with that answer and insisted that Apple should fix it because he could reproduce the problem consistently. The genius emphasized that it was a Comcast issue and that they couldn't do much to help or verify the issue since they don't use Comcast at the store.

Not being an expert in this field, I don't have any advice to offer other than reassuring you that you're not the only one with this issue...sorry. Good luck getting it sorted...Comcast can be a bear to deal with.

 

[deboni]

WildCowboy, thanks for the info. I had seen some other postings by folks who mentioned Comcast, and I know well how hard Comcast can be to get help from. I do have to say, thought, that their internet service is otherwise pretty darned good. I get good results from speakeasy.net/speedtest (>6 mb up, > 1 mb down), and that surely must be enough to run an iChat session. Apple's occasional software upgrades download nice and fast. I manage websites from this machine, and ssh/sftp are pleasingly snappy. So I'm puzzled.

I've posted this matter on Apple's support discussion forums, and the answers I've gotten have to do with firewalls (off), number of NAT's (one at each end), bandwidth settings in iChat Prefs (none) and Quicktime Sys Pref (1.5 mb T1/Lan); all of these have been checked and we're in compliance.

What I can't figure is what might have changed in Comcast's net or peering arrangements in the past year that have caused this problem to surface. It must have to do with connections that are persistent and uniform in their bandwidth needs over time. But I can't get Comcast's attention for long enough to bring these matters up. Think Apple might help? I hope so; I have an appointment at the Emeryville, CA Genius Bar for the day after tomorrow, to discuss the matter.

Tom

 

[deboni]

Follow-up from original poster:

I had an appointment at an Apple Genius Bar where I discussed this matter and another with a staffer there. He told me I'd done all I could with Comcast, and it was time to submit official feedback to the iChat engineering staff at Apple via apple.com/feedback. I did this. We'll see if anything comes of it.

 

[Jopling]

I just moved into a new house and have comcast. The upload speeds are so bad that I can't video chat as well. I receive the other person fine, but my picutre comes across terrible for them.