Downloads stop after a few megabytes

Question

Downloads stop after a few megabytes

I'm guessing this would be a network problem, rather than an OSX problem, but I'll ask here in case.

Lately I haven't been able to download any files more than a few megabytes in size. After downloading a few megabytes the file just stops downloading, and the "time remaining" keeps increasing indefinitely. Sometimes I can stop the download and restart it, and it will continue downloading where I left off, and eventually it will finish downloading after a bunch of cycles of this.

But this morning, I tried to use Software Update to update to iTunes 9, and I'm getting this same problem. But my stopping and starting technique wont work in Software Update. Can anybody give any help on how to get my downloads working right again, or at least on how to download iTunes 9 without Software Update? Thanks

Update: I've just found the download page for itunes 9 on apple.com, and downloading it in Safari works fine, but I'm still having the stopping and starting problem...

Message was edited by: Bill Buchanan

Dual 2.0 G5 Tower, Mac OS X (10.5.5), 1.5 GB RAM, dual monitors, Radeon X800XT video card

Posted on Sep 10, 2009 12:48 PM

Reply

Answer 1

Limnos

Level 10

428,333 points

Sep 10, 2009 1:36 PM in response to Michael Westbourne

Usually when I experience something like that I suspect it is just a network problem elsewhere and there's nothing I can really do about it. I would imagine that after new releases that the servers get pretty busy.

Reply

Answer 2

Camelot

Level 9

58,581 points

Sep 10, 2009 2:45 PM in response to Michael Westbourne

If this is consistent across many sites then it sounds like a network configuration problem - probably in the MTU setting.

The MTU sets the maximum amount of data that can be sent in each packet. If they're mismatched then the server sends data in chunks that are bigger than the network can handle. It may be OK in small bursts (buffering and retransmits take care of it), but at some point (e.g. after several megabytes of data) the server gives up and the connection breaks.

The tricky part is determining what the MTU should be. 1500 is a typical maximum on a LAN, but some links, especially PPPoE and DSL links, require something more like 1460 (or less).

Changing the setting is pretty easy. Just use System Preferences -> Network -> (interface) -> Advanced -> Ethernet -> MTU and lower the number. You might find that trial and error is needed to find the right value, but 1480, 1460, and 1422 are good numbers to start with.

Reply

Answer 3

Sep 25, 2009 1:12 AM in response to Michael Westbourne

I have found the same thing happening to me ever since I attempted to download the iTunes 9 update. The only way for me to complete the updates is to 'stop' then go back and start the install again....sometimes multiple attempts until all the file is downloaded.

I have the same problem on my iMac and Macbook Pro so had the same thought that maybe network related rather than on the apple side. What's got me stumped is that its worked fine for 2+ years and haven't changed the network settings.

if you had any luck in resolving I'd be interested in finding out how you fixed. Thanks

Reply