Apple AirPort Express - Streaming Music on iTunes - Frequent Music Drop out

I think I have found a solution to this problem, at least I think that I have found the solution to my problem, since there may be several things that cause dropouts. I have a G3 iBook as my iTunes player, and I have an Airport Extreme base station as the "main" in a WDS network, and an Airport Express as a "remote", connected to my stereo. When I updated iTunes to 8, and also updated the base stations to 7.4.1 (they are both "n" base stations), I started getting maddening dropouts, anywhere from 10 to 30 seconds, and at a frequency of once a minute to once every 5. It was completely unusable. I thought that it was either RF interference (since iTunes drops out when my microwave is on), or a problem with the base stations switching between 802.11n and 802.11b (since the iBook has an old Airport card). To rule out RF (at least between the iBook and the network), I connected the iBook to the Extreme base station with an Ethernet cable, and the dropouts were the same, so it had nothing to do with the wireless link out of the iBook.

After many many reconfigurations of my home network, I finally decided to have a look at the link with Wireshark to see what was going on. I was very surprised to see that the drop-outs were exactly coincidental with floods of ICMPv6 "neighbour solicitation" messages. It looks to me like the iBook holds up all network traffic while doing IPv6 network discovery operations. I went to the System Preferences screen, selected the Ethernet port, turned off IPv6, and have not had a single drop-out since.

In order to prove that this is causing your problem, you should download the free application Wireshark and do the same thing. Sorry, it's kind of an "experts only" app, but it isn't too difficult to use. In order to make it work, download it and install it. Before you fire it up, you have to open a terminal window and type the following:

$ sudo <username> chown /dev/bpf*

Replace <username> with your computer's account name, which you can always find by typing:

$ whoami

Then, start up Wireshark, and click on the Capture... menu. Depending on which port you are using to stream your iTunes, you will want to monitor en0: or en1:. Play something on iTunes and wait for it to pause. You will see ICMPv6 neighbour solicitation messages showing up on Wireshark during the pause, and then it will go back to iTunes. If this is happening, turn off IPv6 and the drop-outs should disappear.

If you don't want to bother with Wireshark, you could always just try turning off IPv6 and see what happens, but note that in the Apple knowledge database, they say that you must have IPv6 on for iTunes to work. It is exactly the opposite for me, so I don't know why Apple thinks this.

BTW, I actually set up an "expert" call to see if I could get some help. I got the call exactly on time, and the person on the other end of the line was useless.

Thanks Pegres for responding. I think that while IPv6 issues seem plausible - it is spurious in my scenario. Both my MBP and Vista machines w/ ITunes 8.1 cause periodic dropouts. My Windows machine doesn't have IPv6 bound or enabled for it's network adapter.

None of the other nodes on my network are recent enough to have IPv6. It happens when it is only my Windows machine and Airport Express on the network too.

Message was edited by: stephbu

I have been experiencing the same drop-outs with iTunes 8, Windows XP & Airport Express 802.11n (latest firmware).

However, having uninstalled iTunes 8 & reverting to iTunes 7.7 (after some grief) I can now stream to my AX without drop-outs. (No changes to the network or environment.) The only problem I have now is that I can't run both my PC Speakers & the remote together as I get an 'unknown error -15000' when itunes tries to re-connect to the remote speakers! Not perfect, but less annoying than the drop-outs.

All up, not as simple as I'd been led to believe as the original config took a lot of manual mucking around with firewall settings & Cat-5 cable to get the AX talking to the network properly. Still, it looks good!

Cheers,

T.

I spent a lot of money on the airport express base and remote solely for the purpose of streaming my itunes from my computer to my stereo. I took the advice of a google wizard across the street in buying this stuff and he helped set it all up. I do not even have a wireless laptop capability, only a desk top PC. The drop out is catastrophic to its intended purpose (merely listening to music) and I would recommend to anybody thinking of buying these products for this purpose, DO NOT NO MATTER WHAT. I read the above posts and all are far beyond my computer capabilities and they are clearly individual solutions in any case. Get off your duffs Apple and fix this, it is disgraceful.

It's iTunes 8. Doesn't matter what setup you have. Everybody who previously had Airtunes working flawlessly (Windows/Mac) on 7.7 and then upgraded to 8 instantly started having problems with stuttering/dropouts/pauses. Anybody who has rolled back to iTunes 7.7 reports the problem is gone. Unfortunately we're up to 8.2 now and still no fix. Many people have iPhones/iPods that require iTunes 8 and so can't revert to 7.7, aside from library incompatibility. Apple I hope you are reading your feedback emails and doing something about this serious bug

Just to throw some more info into the mix, it may be connected to iTunes 8 somehow but that can't be the whole story. The reason I say this is that my wife and I have near-identical Macbook Pros, both running the same version of iTunes (8.2). They connect to the same set of speakers via the same Airport Express. Yet her music plays fine, whilst mine is 98% drop-out (occasional bursts of sound get through, but it's more like those momentary millisecond-long blasts of static that radio astronomers get so excited about). I should add that in making my comparison tests I ensured that only one of the macs is connecting to the remote speakers at a time, with the other one set to use 'Computer' in iTunes.

I've compared our settings in iTunes preferences and network preferences, and can see no differences between the two machines' settings (apart from the necessary ones like machine-specific ip addresses etc).

The only difference that I can see is that I'm running Leopard 10.5.6 whilst she is on 10.5.7. I'll try and find time to do a backup-and-update on my machine and see if that makes any difference. Otherwise I'm completely stumped.

Update: I moved on up to 10.5.7. It has made no difference. So I'm now stumped as to what the difference can be between my wife's setup my own. One laptop streams through just fine, the other is like trying to tune into enemy transmissions. Ugh.

BTW, sorry, I only just noticed that this is an iTunes for Windows thread. But maybe the info is helpful anyway, I don't know.

Message was edited by: Rick Lecoat