Why are My iTunes Downloads so Slow?

I have a 30 Mbps internet connection. When I run a speed test against my connection I almost always hit 30 Mbps. However, when I download podcasts and other files from iTunes my download speeds max out at just over 7 Mbps. I ran the diagnostics in iTunes and everything checked out fine. Any ideas on why I getting such a slow download speed?

Windows 7

Posted on Apr 17, 2012 5:18 PM

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266 replies

May 19, 2013 2:33 AM in response to eirikandreash

I have no real slowdowns on the net... I can speed test anywhere in the USA and get full bandwidth. So there's no issues between me and apple... I trace route to apple and the avg roundtrips is around 30ms, and it's only about 20 hops


Correct. My priority bandwidth is only to my ISP, but I have no other issues.. It's ONLY with iTunes downloads to my PC, ipad, iPhone.

May 19, 2013 2:50 AM in response to TallBearNC

Maybe ill try lowering the time that cached data can be held.. If iTunes / apple constantly changes downloads, then I need to set my dns cache to expire quickly... However , rebooting, etc never solves my issues... It's just fast one day, slow the next... Super fast for one movie, then the next creeps along... Often I have to pause the download then restart it to get better speed...I guess doing that may get a different ip to DL from...


In any case, apple needs to fix it and guarantee a minimal DL speed


And again ... The more and more I DL in a day, the slower it gets... And that's only iTunes...my ISP doesn't put ANY restrictions on my service as its a business class connection.

May 19, 2013 3:59 AM in response to TallBearNC

To your first post: I have 7 hops, and 10 ms delay, when I traceroute trailers.apple.com. If you have 20 hops and 30 ms, then that is significant more than my records. If I run several traceroutes on http://lg.he.net, I get an average of 4-7 hops. I.e. you have to many.


To your second post: You are right, DNS close by speed things up. BUT. You are not right when you say, "dns is only to start the process". Different CDNs have utilized DNS to optimize content delivery for years. For instance have Akamai low-level DNS servers a TTL on several seconds to one minute. Please read the articles mentioned in my post on May 12th, especially the one from Queue, which ultimately reflects on how CDNs uses DNS in a not intended way. To conclude, you are wrong when you say, "iTunes has the ip and no longer needs dns services". My question, how do you fetch information to your own local DNS, and what happens if you use your ISPs DNS?


To your third post: You are right, lower the time that cached data can be held! But why do you have your own DNS? That will mess things up on several web pages using CDNs [1]. My suggestion is that you try to use your regular DNS - and see if that helps.


The Internet is not perfect, and it is not possible to guarantee a minimal downstream speed, unless you own the network from terminal to terminal. Therefore companies like Apple, buy services from several CDNs to serve people all around the world. These CDNs deal with the congestion problem that is inherent in the Internet. By using several techniques and technologies, the CDNs route around congestion, BGP error, and cable cuts. Also bringing content closer, so that througput will increase.


[1] http://www.cdnplanet.com/blog/which-cdns-support-edns-client-subnet/

May 19, 2013 8:12 PM in response to Griff1324

Having slowness when downloading from iTunes via my Comcast cable connection at home. iTunes says that it will be 17 hours to download my movie. Speedtest shows 51.16Mb down and 11.21Mb up, so it's not a bandwidth problem. Recognized that I am in fact using OpenDNS. Changed to my regular Comcast DNS (68.87.85.98 and 68.87.69.146) and found that after quitting and relaunching iTunes, it says 29 minutes remaining. Knowing how DNS works leads me to think that the DNS service that is being employed _SHOULDN'T_ matter, but experience is proving to me otherwise.


In short, changing my DNS settings sped up my iTunes performance. Go figure.

May 20, 2013 12:42 AM in response to Josh Ausborne

Josh Ausborne wrote:


In short, changing my DNS settings sped up my iTunes performance. Go figure.


Very good! In short: Akamai and Level 3 connect you to a cache server based on your DNS servers IP. If you are in NY, and the DNS server is in LA, well, then you are served from LA. Bottom line is, DNS matters.


If you would like to have more insight in the subject, I suggest the section in "The Next Page"[1] from page 8-15, or Paul Vixies article "What DNS Is Not" [2].


[1] http://www.nsa.gov/research/tnw/tnw183/articles/pdfs/TNW_18_3_Web.pdf

[2] http://queue.acm.org/detail.cfm?id=1647302

May 20, 2013 1:08 AM in response to eirikandreash

Clearly as much as you many would like to make this a technical issue, it isn't its a business issue.


People, me included have been upset with the download speeds of movies and many will not use Apple to stream rented movies into the future because of this.


Now I live in the UK a small island with 60-70 million people. I live in a high populated area which is well served by internet, I get 50mbs.


My expectation of time to download a movie is 20 minutes maximum, which is poor level of service when compared to Netflix, ILovefilm etc.


Of course if Apple does not want to extend its service to the UK, put in servers located to the major network hubs etc then I really would prefer that either:


a) Apple indicated that service quality is poor in my area


b) Apple did not offer the service in my area.


Then my expectations would be lower and I would use the service with lower expectation probably as a l;ast resort.


Now as a technologist and IT software engineer I know quite a lot about computing but do not claim to be networking expert.


But when I am in relaxing in "Consumer" mode I don't want to worry about how my DNS is set up, which really should need to be altered for using a service such as Apple.


Afterall I don't need to update when using Netflix or ILoveFilm.


Therefore I have written off Apple as a supplier for movies until I get a sensible answer direcetd at the consumer level explaining why they have had problems and what they intend to do into the future.


It's a problem of expectation, Apple are failing in this area in the area of movies.

May 20, 2013 1:53 AM in response to AJSouthall

AJSouthall wrote:


Clearly as much as you many would like to make this a technical issue, it isn't its a business issue.


Well, I disagree. It is a technical issue, but these problems are solvable with different business agreements, e.g. using CDNs to cache content closer to the user. Apple does that, but they do not own the entire network. As such, they cannot guarantee for your speed. But they can do as much as possible to eliminate the problems that is inherent in the Internet, like congestion - which they do.


You don't need to worry about your DNS. But if you have changed your DNS prior to using iTunes, you need to understand that it will affect download speed. Also, bear in mind that your bandwith speed is not equal to your actual throughput[2].


Can I ask what kind of DNS you are using? How many hops do you get to the server that actually serves you on both Ilovefilm and Netflix[1]? I bet that you don't get 50 Mbit to either of these in actual throughput. But you can of course get better QoE, if Netflix and Ilovefilm have placed servers inside your ISPs network, and Akamai has not. What kind of ISP do you use?


[1] http://ispspeedindex.netflix.com/uk

[2] http://en.wikipedia.org/wiki/Throughput

May 20, 2013 2:11 AM in response to eirikandreash

I feel this DNS business is getting overplayed in this discussion and is marketed as a "fits all"-solution. Which it is not. I never changed my DNS and as I've reported I feel downloads via iTunes take too long time even if they are not dead slow. Software updates from Apple is much faster.


Great services should mean fast downloads. Apple and outfits like Akamai are all over the world and together should be able to cache at least popular films near the viewers also with some anticipation, no matter where they are geographically.

May 20, 2013 7:39 AM in response to AJSouthall

Look, I use several services including Netflix and Amazon. They stream and in the case of Amazon, download well. However itunes movies sometimes take days to complete.

Why should I be asked to do detailed investigations into my operating system and my ISP network which require

expertise beyond a normal user.?

I get the same lame advice when I raise the topic or itunes hanging my computer especially when syncing.

I don't have Apple tv - tell me - is Apple streaming the same miserable process as Apple downloading?

May 20, 2013 7:47 AM in response to Bocaj Ydobaep

Its laughable.


I used to be Global Ecoomerce Tech Manager for a large multinational business.


Albeit not as big as Apple. But if that business was running this show the service would be pulled.


Or operated only in those locations that the service could be of a good service level.


With respect these people talking about DNS are off their trolley !!


If national newspapers got hold of this story.....hmmm...maybe I will just send them it !!

May 21, 2013 12:58 PM in response to eirikandreash

1) swcdn.apple.com -> 50.270 ms in 8 hops, trailers.apple.com -> 306.196 ms in also 8 hops and more interestingly a1442.v.phobos.apple.com from where I believe I downloaded my last rental HD -> 67.122 ms in 8 hops.



2) Which ISP do you use?

Tele2 (Big swedish reliable ISP)


3) How long time does a regular movie take to download?


from the web a DVD-sized HD movie like "PressPausePlay" takes around 2 hours. From iTMS it took 3 hours for roughly the same size.


4) How long time do you expect it to take?

2 hours at best at my current connection speed*, but if I had 24-32mbit connection around half an hour would be decent depending on circumstances.

Nothing else was using the net during the download as I wanted the movie ASAP.

May 22, 2013 12:36 AM in response to Mik B

1) Interesting results. Numbers of hops (a1442.v.phobos.apple.com) is similar to what I get in Norway using Uninett. But I get slightly lower round trip time, around 10 ms +/- 20% when using Uninett:


4 se-tug.nordu.net (109.105.102.21) 8.914 ms 8.831 ms 9.397 ms

5 se-fre.nordu.net (109.105.97.1) 23.490 ms 9.306 ms 9.193 ms

6 * s-b3-link.telia.net (213.248.97.17) 11.580 ms 8.975 ms

7 80-239-254-58.customer.teliacarrier.com (80.239.254.58) 9.032 ms 9.333 ms 11.615 ms


You are not served from a1442.v.phobos.apple.com. That is just a CNAME (alias) for a1442.v.phobos.apple.com.edgesuite.net - which is a DNS server for Akamai. Are you able to post parts of your traceroute here? You can hide your own IP, but it is interesting to look from where you actually are served.


2) Do they prioritize traffic? I am not sure if you have net neutrality rules in Sweden?


3) I agree that is too slow. But 2 hours is also slow.


4) Seems reasonable. 4 GB will use approximately 1 hour on 10 Mbit. But bear in mind that if you have significant overhead in your network (it seems like that), the mathematical calculations won't necessarily matches practice.

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