iChat MAC to PC Video Freeze after 6.5 min

Yep,

See here,
http://docs.info.apple.com/article.html?artnum=93245

Let me quote YOU, James... from your previous posting, the CAPS are mine:

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While I agree that there could be a software problem in iChat, I don't think it is in connection with AIM. This problem usually or perhaps only appears when the PC or Mac (I've seen this happen on Mac to Mac connections) user on the problem end has CABLE INTERNET SERVICE AS OPPOSED TO DSL.

It ALMOST ALWAYS involves a high-speed CABLE CONNECTION, and sometimes the problem will go away if the cable modem is swapped out for another brand of modem.

I think the problem is the interaction of iChat and the CABLE MODEM and CABLE INTERNET SERVICE on the other end.

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Other than telling me to have my friends switch internet service providers, switch to DSL or trade out their modems, do you have anything USEFUL to suggest?

I'm afraid you've lost me. Perhaps someone else can help you.

Hi,

Do a find for Pith Helmet.

Ralph

We'll see...

JIm,

IS it just this one PC that this happens to.

Ralph

yes

Jim

Hi Jim,

This is very strange.

The original poster (James) had a partially successful contact from another PC but had no Audio so we can't rule out a bandwidth problem.

We know that once a Video or Audio chat is finally connected it is peer to peer.
This leaves at least two ISP servers in the loop and more likely more for the hops in between.

The problem only seem to happen at the Mac end.

It does not just effect Dual 1.25Ghz machines as John has an iMac.

No-one is reporting that they get there public IP address from an external DHCP server. (Dave particularly answers this question).

The timing seems to start when the chat becomes peer to peer.

For those it happens to it is always at the same time.

I think it happens to international chats only.

We don't know the all the ISPs involved or what sort of service people have. (except John who says he has tried his works T1 line).

I think people need to do a trace route of some kind and see if they are bumping into a server that Macs don't like for some reason.

That will take time that some people may not want to spend on this.

Other ideas are a bit far fetched.

Old bit of of Software Firewalls and Virus checkers (someone reported this not too long ago.) A background part was still active despite the application being trashed.

Some have reported problems with an app called Pith Helmet ( I forget what it was to do with but this was another remnant, possibly peer to peer).

There seems to have been problems with the AIM servers in the past few days.
Not sure how tis would effect something that we are told is peer to peer.

Not much help I'm afraid.

But maybe some ideas.

Ralph

It's not just an "international" problem... unless Southern California is a different country (as I've always suspected) from Centrao California.

Ralph - I'm pretty sure this problem isn't related to the connection being international. The collegue I'm chatting with is in Archway London N19 and I'm in Angel London N1.

We're both also on BT broadband, though I'm on the business broadband platform and he's on the BY/Yahoo platform. The DHCP lease idea is interesting - after all, if either of our ISPs allocated us a new public IP address during a chat, the streams would stop. But, both streams would stop. So I think its a non-starter. From checking my dynds.org logs I'm pretty sure my WAN IP address only changes when I log into my ADSL connection and at no other time.

The only way to troubleshoot this problem that I can think of would be to check for incoming RTSP video packets once the the connection has frozen on the mac (using Interachy for example). If no incoming packets are being received by the Mac, the RTSP stream from the AIM far side has quite obviously stopped flowing. If packets are still being received but no new video is being displayed perhaps the packets are no longer being interpreted correctly or are perhaps corrupt. It'd be hard to say which client would be at fault in either situation though.

I'll give that a go next time I talk to my collegue.

Regards
Dave

Hi Ralph,

You ideas often turn into solutions! The list of specifics seems a logical approach to me. I offer the following additional comments from my case:

re: your comment:

I think it happens to international chats only.

If by "international" you mean outside the UK? My video problem is between two states in the USA, so my ONLY freeze is unrelated to crossing national borders.

re: your comment:

It does not just effect Dual 1.25Ghz machines as John has an iMac.

Right. It effects my Dual 1.8Ghz, too. (Last year's model, not the current one.)

re: your comment:

... problems with an app called Pith Helmet ...

I do not have, nor have I ever had, PithHelmet on any of my Macs. ("PithHelmet" is a non-Apple ad (not pop-up) blocker for Safari.)

re: your comment:

...problems with the AIM servers in the past few days...

My freezer is exactly the same now as in my first video with this one PC -- over a MONTH ago.

I have our cable modem info:
My (Mac) Cable Modem: BestData Cable Modem, Model: CMX 110
PC Buddy's Cable Modem: Toshiba, Model: PCX 2200

re: your comment:

We don't know the all the ISPs involved or what sort of service people have...

My PC contact that freezes and I both are on cable. Different cable companies serve our respective cities. IF you want us to report the names of our cable companies, I can get that info.

Yesterday's schedules precluded us from testing our only remaining question. My PC friend has turned off his Outlook setting that had been (we think) automatically checking for mail every 5 minutes. We will try video with the setting "off", see whether the freeze goes away, and post back the results.

Jim

Hi Jim,

Dave replied earlier and said he was having problems with the UK.

References like SoCal do not mean anything to me I'm afraid so I had erroneously concentrated on the ones that did mention international contact (any one country to another not just away from me).

I think it is likely to be something that is running on the Macs involved.... but as James said it seems to involve a combination of things.

For instance do people have iTunes open in the background ? iChat shuts down the Volume from iTunes when a Video or Audio chat starts. Does anyone know how often it checks in with the music store ? It does when it launches.

What about iPhoto ?

Is anyone getting their time from an Apple Server ?
How often does that check ?

You have to have Quicktime 6.(something) for iChat to work. Has everyone got their connection rates set high enough ?

Does anyone know what style/format the AIM application sends data in for both Audio and Video ?

Just trying to make this box as big as possible and think outside that as well.

Do cable modems still use At&T protocols ?

Ralph

Ralph,

Good thoughts. My responses where I might offer anything
b possibly
useful:

I respect your idea that something running on the Macs is likely to be at least part of the cause. Your question about background apps is a good one. For instance, I seldom open iTunes or iPhoto, and I NEVER have either running while iChatting. However, there are other possibilities, perhaps as simple as an item running from startup. In my case, I have iCalAlarmScheduler, iChat, and an Epson Scanner Monitor installed as Startup Items. I am going to delete them all right now and include a test to see whether that effects my freeze when I do my next video IM with the one PC with whom I have a problem.

Moreover, I always try not to focus too narrowly on one solution when I do not KNOW what the problem is, but rather only what the symptoms are. For instance, although it has been asserted that this is a glitch in iChat's video module, I have seen no PROOF that, even if this assertion is true, the PC end is not doing something to trigger the event. Recall that I video with several PCs, but with only ONE do I experience the freeze. How can that be solely my Mac's problem? I will try to keep an open mind while troubleshooting continues to further reduce the list of possible problems.

I DO get my time from Apple Server (doesn't everyone with Panther if you are connected to the web?), but I do not know how to determine or adjust how often OS X checks.

My Quicktime 6 connection rate set at 1 Mbps Cable, which is probably HIGHER than my service actually delivers.

I cannot think of any other useful info that I can offer until my next video test results with my PC freezer friend (sorry, John, couldn't resist...)

Hope this helps somehow, Ralph.

Jim

It is clear that background timer activity is not the cause of the lost video. If the time between the beginning of the video chat and the video "freeze" varied from chat to chat, but was never more that a specific time, then a timer running in the background could be the cause. If I started a chat 1 minute before some hidden process was about to do its "thing", then my chat would last for 1 minute. If I started my chat 5 minutes before the hidden process was activated, then my chat would last 5 minutes.

The time from the beginning of MY video chats to the video "freeze" is always 5 minutes and 10 seconds, regardless of when the chat begins. So processes (external to iChat) that have periodic timed bursts of activity are not to blame.

It doesn't matter whether the periodic activity is on a server, my machine, or my friend's machine. If it's occuring at a specific timed interval, it is not causing the lost video.

I've had video and audio interfered with during an upload or download, but it resumed nicely afterwards. I'm chatting with a friend 400 miles away, across no borders or boundaries... except the Mac to PC and DSL to cable internet boundaries. Since there is no video "freeze" on the AIM/PC end of the chat and the timing of the "freeze" is completely dependent on the time the chat goes peer-to-peer, the start of the actual two-way communication, it MUST be an issue with the way iChat operates in this context.

Hi John,

I follow the logic of this.

That would exclude-
Date /time settings from another server.
A background app that was already in progress.
Any remnant part of an app that might be running in the background as above.

I do not feel we can run out other servers providing the hops to the other end of peer to peer contact, although I feel this is less likely.

AS it does not happen to all contacts to PCs from Macs I don't see that it can be just the iChat application.

I do not have cable and have spent no time in looking at how it works. I know that some people have routers after their cable modem. So I don't feel we can rule out some sort of lease time component.

What we also don't know is - if those PC users that this happens with also have problems of a similar nature with other iChat users or is is only ever between the two people who discover they have this problem ??

Just more thoughts at the moment.

Ralph