Note: After publishing this article, I was given the results of traceroutes from other Australian cities. The results showed I was wrong.
Over on Twitter @bobearth, prompted me to run some trace routes against the Google CDN and compare it to the Microsoft CDN. It appears Google have taken the distributed network out of their CDN.
As you’re probably aware, CDN is an abbreviation for content distributed network. The idea behind them is that American users will be served content from a server located in the US or Canada, Australian users will be served content from a server located in Australia or the Pacific, and so on.
Doing a trace to the Google CDN from the Soupgiant HQ in Melbourne, I was expecting to receive a response a server in Sydney. Instead, the response came from California, USA as the final steps of this
127.0.0.1:~ peterwilson$ traceroute ajax.googleapis.com [snip] 5 syd-nxg-men-crt1-ge-3-1-0 (220.127.116.11) 27.479 ms 87.472 ms 78.234 ms 6 18.104.22.168 (22.214.171.124) 91.118 ms 31.786 ms 27.314 ms 7 126.96.36.199 (188.8.131.52) 80.358 ms 184.108.40.206 (220.127.116.11) 27.842 ms 18.104.22.168 (22.214.171.124) 44.059 ms 8 126.96.36.199 (188.8.131.52) 177.570 ms 184.108.40.206 (220.127.116.11) 172.656 ms 157.311 ms 9 18.104.22.168 (22.214.171.124) 172.117 ms 153.304 ms 180.227 ms 10 googleapis.l.google.com (126.96.36.199) 178.725 ms 193.939 ms 181.227 ms
The response from Microsoft’s CDN were more to my liking:
127-0-0-1:~ peterwilson$ traceroute ajax.aspnetcdn.com traceroute: Warning: ajax.aspnetcdn.com has multiple addresses; using 188.8.131.52 traceroute to ajax.aspnetcdn.com (184.108.40.206), 64 hops max, 52 byte packets [snip] 7 10gigabitethernet5-1.syd-xmx-edgcom-1b.ntwk.msn.net (220.127.116.11) 90.691 ms 86.004 ms 37.900 ms 8 ajax.microsoft.com (18.104.22.168) 71.541 ms 83.053 ms 80.586 ms
This prompts the question: should I switch to serving jQuery and other hosted libraries to the Microsoft CDN? Both Google and Microsoft use a cookie-free domain for their CDNs, both are set to browser cache for 12 months. More sites use Google’s CDN to serve, but only Microsoft serve geographically near the majority of visitors to Soupgiant and Big Red Tin.
I don’t know the answer to this question. I do know that if Google’s CDN was distributed, there would be no question.