Q: Why are My iTunes Downloads so Slow?

Even my i devices are slow when using the app and iTunes apps :(

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.

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

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.

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

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.

The reason for bringing up the facts about DNS, was that many in the discussion had misconceptions about how content is delivered, and DNS has implications for download speed. But if that does not solve your issue, we could try something else.

1) If you run "traceroute swcdn.apple.com" - and "traceroute trailers.apple.com".

• What is the result?
• How many hops?

2) Which ISP do you use?

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

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

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?

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 !!

Well, I just offered my help. This is a support forum, not a complaints department.

Can you please explain to me why DNS does not affect downstream traffic? If you would like to get some help on this forum, please feel free to give some more information about your ISP, which DNS you are using and eventually how many hops you get before you reach e.g. trailers.apple.com or swcdn.apple.com.

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.

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.

These are the results for me here in the Netherlands...

traceroute: Warning: a1442.v.phobos.apple.com.edgesuite.net has multiple addresses; using 65.172.31.51

traceroute to a1442.w11.akamai.net (65.172.31.51), 64 hops max, 72 byte packets

1  192.168.2.254 (192.168.2.254)  1.305 ms  1.015 ms  0.840 ms

2  195.190.241.14 (195.190.241.14)  41.047 ms  37.310 ms  40.921 ms

3  nl-asd-dc2-ice-ir02.kpn.net (213.75.1.66)  45.777 ms  42.789 ms  47.825 ms

4  nl-asd-dc2-ice-ir02.kpn.net (213.75.1.66)  48.582 ms  47.086 ms  47.821 ms

5  nl-asd-dc2-ice-ir01.kpn.net (213.75.1.146)  41.676 ms  38.095 ms  48.001 ms

6  asd2-rou-1022.nl.eurorings.net (134.222.93.138)  36.768 ms  45.289 ms  36.520 ms

7  nyk-s1-rou-1001.us.eurorings.net (134.222.231.230)  125.279 ms  125.147 ms  124.979 ms

8  nyk-s1-rou-1021.us.eurorings.net (134.222.231.238)  120.605 ms  120.313 ms  120.231 ms

9  ahbn-s1-rou-1001.us.eurorings.net (134.222.232.34)  124.779 ms  137.846 ms  125.954 ms

10  ahbn-s1-rou-1041.us.eurorings.net (134.222.231.121)  125.196 ms  124.785 ms  124.819 ms

11  sl-st31-ash-.sprintlink.net (144.228.205.37)  125.857 ms  125.830 ms  125.442 ms

12  sl-crs2-dc-0-13-0-0.sprintlink.net (144.232.25.14)  127.751 ms  127.302 ms  127.398 ms

13  sl-crs2-rly-0-0-3-0.sprintlink.net (144.232.8.165)  129.270 ms  129.528 ms  129.914 ms

14  144.232.4.186 (144.232.4.186)  143.139 ms  142.337 ms  142.351 ms

15  144.232.20.187 (144.232.20.187)  142.701 ms  143.844 ms  143.212 ms

16  144.232.1.104 (144.232.1.104)  141.983 ms  142.265 ms  141.970 ms

17  65.172.31.51 (65.172.31.51)  142.205 ms  142.755 ms  142.584 ms

I don't know how to interperate these readings... 

Try to traceroute swcdn.apple.com or trailers.apple.com instead. That will give a more realistic picture from your position.