I recently had a requirement to provision an application within Amazon EC2. The web based application was going to be accessed primarily by Australian users, and as a result I wanted to know which of Amazon’s 7 public regions would be likely to provide the lowest latency for users accessing the application.
To do this I provisioned a Micro instance (t1.micro) in each of the following regions:
- Asia Pacific (Singapore)
- Asia Pacific (Tokyo)
- EU (Ireland)
- South America (São Paulo)
- US East (Northern Virginia)
- US West (Oregon)
- US West (Northern California)
Once the instances were online I then took the top six Australian ISPs according to Broadband Choice, which at the time of writing are (in alphabetical order):
I also added Vocus Communications to the mix as a popular provider of IP transit services within Australia.
From each of these providers I ran a series of tests to test the latency and the number of network hops between their network and the Amazon EC2 instance. Tests for all providers were ran from the east coast (Sydney or Melbourne), for providers such as Internode with direct connectivity on cable systems such as SMW3 to Singapore, you might expect lower latency to the Singapore region from Perth.
With the tests run, here are the results:
You can instantly exclude EU and South America for Australian users, the average latency is just too high. US East (Virginia) is a possibility, but again the latency is quite high and users are likely to find applications are simply too slow.
Singapore has the lowest latency of all regions depending on the ISP. Users on Internode, Optus and with providers utilising Vocus bandwidth should find performance quite acceptable. Unfortunately for other providers such as Exetel and TPG the performance isn’t quite so good, most likely due to a path in one direction travelling via the USA.
US West (Northern California) has the most consistent latency, with all ISPs around the 150-180ms point. This means that users across all ISPs should have acceptable performance.
In this instance I decided to go with US West (Northern California) for my application due to its consistent latency across the board. Singapore was a close contender, however more testing might be required to ensure that there aren’t any other ISPs that experience latency beyond 200ms.