If you’re experiencing really slow downloads from the iTunes store on TELUS Optik, it could be a problem with your DNS servers. I think by default the DHCP server on the Optik router configures the clients to use the router as their DNS server. The router is configured to use the servers:
- 18.104.22.168 (ns1.dns.telus.com)
- 22.214.171.124 (ns2.dns.telus.com)
I think that either the Optik router or the TELUS DNS servers are a bottleneck here. I guess that for some reason, iTunes needs to do a lot of DNS lookups when it transfers data?
Anyways I changed my clients to use the following DNS servers:
The first two are provided by Google, the last two are provided by OpenDNS. iTunes download speed went from ~200KB/sec to ~1.5MB/sec. On Mac OS X, change the setting in System Preferences → Network → (Select your Network Connection) → Advanced → DNS.