Designing high performance mobile sites presents a whole host of considerations – the main two being the size of the screen and the fact that the network connection is over a 3G or 4G network, or now the LTE network.
In last month’s analysis of mobile performance we also briefly touched on the role of CDNs (Content Delivery Networks) and how these take on an even more important role in mobile design. They are a critical method for optimizing performance. But like anything in web design, they can have both a positive and negative effect if not done correctly.
A content delivery network, or content distribution network (CDN), is a large distributed system of servers deployed in multiple data centers across the Internet. The goal is to serve content to end-users with high availability and high performance by having a highly distributed network which can adapt to high and low demand quickly.
CDNs serve a large fraction of the Internet content today, including web objects (text, graphics and scripts), downloadable objects (media files, software, documents), applications (e-commerce, portals), live streaming media, on-demand streaming media, and social networks. A CDN operator gets paid by content providers, such as the major lodging sites, for delivering content to end-users as effectively or as optimized as possible.
Today it is a recognized best practice using CDNs, especially to avoid latency issues with mobile devices. It’s a recognized global technique and particularly when operating in areas where the network connection might be spotty.
Typically in the mobile world, the sites with the largest amount of content are usually the slowest. But this isn’t always the case due to the effective implementation of a CDN.
On the index, for example, Harrah’s is one of the largest sites (3Mb) yet it actually loads faster than a smaller site like Accor. In this instance, the CDN helps Harrah’s dramatically. But Accor is also using CDN, just not as effectively.
Harrah’s performance is significantly better than Accor’s: 11.62 seconds versus 15.98 seconds. Yet Harrah’s site is larger both in terms of total element size (2958kB versus 1648kB) and number of page elements (208 versus 171). This suggests that Accor is getting outperformed both in terms of how quickly connections are made to the CDN and how quickly the content is downloaded.
So obviously, not all CDNs are created equal. The world class, industry standard ones offer a global presence, intelligent routing and consistent performance over time and geographies.
The popular, top tier CDNs would include Akamai and Limelight. Akamai, for example, uses intelligent routing in how it routes traffic to edge servers.
This adds another dimension to site measurement too. As well as monitoring your site, you also need to monitor your CDN. Monitor the performance of your site as downloaded from the CDN as well as without using the CDN (that is, from your own origin server), plus from a number of geographies. Look at how performance of the CDN and origin are trending over time, and make sure that the CDN is delivering consistently better performance at each location. If it isn’t, then it isn’t adding the value it’s supposed to.
Those lodging sites lower down the index frequently show up with CDN problems evident, most often due to poor geographic coverage and a lack of intelligent routing.
So – clearly large global sites such as those on the Lodging Index can make it better for their mobile customers by having well-tuned CDN implementations.
Anyone can also sign up for a free weekly email delivery of the Keynote Lodging Performance Index. Use it to track how your company’s performance is doing against the competition, or just to follow what some of the major names are setting as performance standards. Keynote runs a large number of US and global Indexes, across a range of industries and government, which many organizations use as the benchmark to achieve their own optimum Web performance.