Question

I am building a site for yacht crews. The client brief expects a dynamic site with mucho user-generated content packaged into a smoking hot design with (knowing the agency) fat weighty images and photos.

But … I want to take into account that visitors will be sometimes accessing over satellite internet connections like VSAT and sometimes high broadband marina wifi. They will also likely be using old hardware and browsers.

Firstly, my knowledge of satellite internet tech is non-existent. Am I right that the bandwidth is not so bad these days, but latency the biggest issue? Can anyone link me up to some info that I would understand?

Secondly, I understand that low bandwidth connections benefit from using css sprites and ajax calls to avoid page reloads. Is that the same for low bandwidth high latency sites? I predict many fancy-shmancy edit-in-place textboxes and the fetching of RSS feeds – how much ajax is too much ajax?

In short, how can I optimise it all for the connection limitations?

Answer 1

Yahoo! defined some rules to improve site performance. Firstly, I suggest you read that set of rules and make use of them whenever you can because they are quite helpful in increasing site performance for most of the cases. See Best Practices for Speeding Up Your Web Site. You can use Yahoo!Slow to measure the overall performance of the site and to profile which parts of the page take much time to load.

Regarding the AJAXifying issue, let me try to summarize the main rules that I keep in mind when developing AJAX supported sites:

1. Main components on the site should be ready when the page is initially loaded and the layout should not be broken so that once the page is loaded, the user will be able to display a well formed page.
2. If you have a long page that shows a vertical scroll, you can load the lower parts of your page using AJAX. This is what facebook does, loads some of the page first and as you scroll down it loads additional data using AJAX.
3. If there are functionalities that may not be used by most of the users, load those contents using AJAX.

And keep in mind that you always have the chance to load content as soon as body load is complete, which means you don’t need to wait for user interaction to load content, thus the users don’t need to wait for AJAX response!

If you think that latency will be the main problem, then you should consider using CSS sprites seriously since it decreases the requests made to the server substantially.