Apple Moves To Dual CDN Vendor Strategy: Now Using Limelight With Akamai

For many years, Apple has relied on Akamai to deliver the vast majority, if not all, of Apple's content. But in the fourth quarter of 2008, it appears that Apple moved to a dual-vendor strategy and started using Limelight Networks in addition to Akamai for the delivery of OSX software updates, iPhone updates and app delivery from and the iPhone store.

Starting in the fourth quarter of 08, content that I historically saw being delivered from Akamai, also started coming from Limelight Networks. Now I don't know if this content was "exclusive" to Akamai or if 100% of it historically came from Akamai, but as an example, in Q2 of 08, my OSX updates always came from Akamai domains. Last Friday, Apple released an update to QuickTime, version 7.6, and the update came from the Limelight network out of a Seattle POP. (

I don't know what parameters Apple uses to decide how they redirect a user's request to one CDN over another, but it appears much of it could be based on the geographic location the user is coming from as I also noticed this exact same QuickTime update getting delivered from Akamai depending on what city the user was located in.

I saw this dual-vendor approach happening across many different pieces of content for Apple including OSX updates, application downloads from the site (like the iLife trial) iPhones software updates and some apps for the iPhone app store.

I started noticing all of these changes around the November time frame and didn't see a single piece of content being delivered for Apple, by Limelight, anytime before that. That's not to say it could not of been happening earlier, but I am one of those Apple freaks who downloads tons of stuff, always looking at where it comes from and have never seen the domain show up anywhere before November.

In addition to this, I also saw the Limelight domain showing up for a limited time for HD videos coming from the site, mostly around the holiday time last year. Tracing tons of that content now only shows me Akamai domains though, so I don't know if that is still happening.

It is also interesting to note that Apple's change to a dual-vendor strategy comes soon after Apple had major issues with the iPhone 3G launch and the MobileMe offering after experiencing outages with both services in the third quarter of last year. However, I don't know if either of these problems were a result of an outage or capacity issue on the network since Apple didn't say why the services went down. And while both Akamai and Limelight told me "no comment" when I asked them for details on delivering content for Apple, Akamai did go on record to say "Akamai had no service issues on our network in Q3 of 2008".

But the fact that the domain is starting to show up for some of Apple's downloads shows Apple is looking to rely less on just one CDN to handle all of their traffic requirements which makes sense if you want to ensure you always have enough capacity. I don't know Apple's traffic volume, but considering how many iPods and iPhones they keep selling, you have to imagine their traffic has some crazy growth each quarter and moving to a dual-vendor strategy should help keep Apple's services from having future performance issues. We already know that no CDN has unlimited capacity and can only handle so much traffic at any given time and if you are Apple, using more than one CDN is just smart business.

Now one could speculate that Limelight only has a very small fraction of Apple's business. That may or may not be true, we don't know. But even if it's only a small percentage, a small percentage of Apple's traffic is huge considering how much volume Apple must be doing every month. And for most customers who move to a dual-vendor strategy, they don't put only a small amount of traffic with one vendor as that defeats the whole purpose of why you have a dual-vendor strategy to begin with. What financial impact Apple's move to a dual-vendor approach has on either Limelight or Akamai is yet unknown, and I don't know any of the contract details.

Quite often I am asked if most content owners use more than one CDN vendor for video or if what we are seeing by Apple is a trend. It's really hard to answer that question since some content owners tell me that using two vendors is a hassle due to having to two contracts, two sets of raw logs, two kinds of reporting etc. But other customers tell me they never want to rely on just one vendor and using two CDNs is essential to their business. That said, I have noticed that lately, it seems many of the big content portals do seem to be using two vendors, but not all of them.

I also think this move by Apple is a testament to both Akamai and Limelight's network performance, specific to video downloads. While I am sure both companies would disagree with me when I say that they both offer a similar level of performance on their network, the fact is that most customers tell me they see very little difference between the two networks for commoditized video delivery services, as it pertains to network performance.

In terms of pricing, reporting and other services outside of simple video downloads there are plenty of differences between the two companies. But if any customer is willing to give both CDNs the same type of video content for simple downloads, clearly the customer trusts both networks and does not see a big difference between the two in terms of performance, especially if they are sharing the traffic.

  • We are seeing more requirements for load balancing 2x CDNs by geographical region reflecting the performance gains some CDNs offer over others in a particular region such as Asia Pacific. Setting up a second CDN for load share, overflow or global load balancing is fairly straight forward so its easy for customers to see what performance or reliability gains could be achieved with a dual vendor approach.

  • Dan,
    Can you give us a quick explanation on how you access the routing data (ie. to see which CDN the download is coming from.

  • Hi Donna, for the QuickTime 7.6 update, all I did was initiate the update from my OSX software update panel and used a program called Little Snitch to see the connection. You can also do it by opening up the terminal window in the Mac as well.

  • B

    I seem to recall this being widely discussed last year, and that it was Akamai (not Apple), in an agreement with Limelight to use their infrastructure when appropriate. (traffic load, etc)

  • LOL QuickTime updates. I wonder what the demand is for those OUTSIDE of its inclusion in iTunes. I seem to remember a product called streamOS that used to use multiple CDNs back in the day….. 🙂

  • Mark

    I also heard of a product called MetaCDN which essentially monitors CDN or cloud storage (S3, Nirvanix) to determine best source/route. But, I assume would add latency since needs to resolve their customer’s links via DNS.
    Wouldn’t this also mean doubling-up on origin costs as would need to save and have your files accessible to both delivery networks?

  • if customer can use different domains for different region and CDN vendor accordingly. multi-CDN stracuture can work very smoothly. that is mostly how I work with customers. we cover the region others can not, mainland China.

  • Kevin

    Dan, I’m not sure where else to ask you about this so I’ll do it here.
    A month or so ago there was a press release about Limelight getting business from Toyota. However to this today I don’t see LLNW delivering anything from Toyota’s website. It still looks like Akamai is delivery everything. Do you know anything about this?

  • Hi Kevin, the release by Limelight says that the CDN services taken by Toyota are for – It’s business they won in Japan, not the U.S.

  • spif

    One of Akamai’s farms hosted at Qwest, netblock, was down (or at least unreachable) last night. I had to put in a forwarding zone in my DNS servers to get pointed to a different farm. Not sure if this is related to the changeover or just pure coincidence, but I thought it was interesting timing.

  • Gregory W.

    Thanks for the post, and for the insights.
    You seem to be saying that Apple is not necessarily unhappy with Akamai’s service, but that the sheer growth in CDN traffic (due, no doubt, to the growth in demand of products by companies like Apple) has convinced Apple to take the first steps toward a dual vendor strategy (from Akamai only to Akamai/Limelight).
    I have two questions regarding this:
    1) Is my analysis of what you are saying – that this is more a situation of Apple needing more CDN capacity than one CDN provider (Akamai) can provide, than a case of Apple being unhappy with Akamai – a valid one?
    2) Can you tell us why Limelight was chosen – from among all the other CDN providers – by Apple to be the second CDN vendor?
    Many thanks for your answers to these questions.

  • jeux wii

    I have a query that is why Limelight was chosen – from among all the other CDN providers? Can anyone answer it? I would like to say thanks to him/her in advance. I like this site.

  • Is anyone else besdies us experiencing problems with Quicktime delivery (extreme picture mangling)? Both our newly encoded QTs and our QTS that have been online and working well for some time have been seriously affected since September 2009.

  • Sathya

    hi Dan!
    Does Akamai & Limelight used for the itune store? How this gets connected to Telcom Carrier (ATT & soon Verizon) Mobile Infrastructure? I mean when u use any App from ur iPhone I believe it goes from the telecom carrier pipe towards Apple CDN? Does Apple have to pay ATT for the interconnect?