If you own a Sonos system outside the US and access Pandora then you'll have been disappointed when Pandora restricted non-US ip addresses from accessing the service with a 'deeply sorry' message.
A US customer of ours who visits the UK regularly approached us to see if we could provide access whilst abroad.
The solution that we came up with is remarkably simple.
It comprises of a Draytek 2820 dsl router/firewall and a PPTP VPN account with one of various providers. In this case we used Witopia who offer a PPTP VPN service which terminates in the US.
An overview of how this works is as follows:
The Draytek 2820 is the default gateway for the internal network and provides regular internet access. The Sonos zoneplayers are on the internal network along with the other computers.
The draytek is configured with lan to lan pptp vpn to Witopia and has the ip ranges of Pandora configure. Any network traffic from the internal network requesting services from Pandora will get routed across the VPN and appear as though it is coming from the US. All other internet traffic is routed normally through the ISP.
2. You'll need to setup the PPTP VPN account from Witopia. This will provide you with a username and password. pptp.witopia.net is the hostname we will need as well.
3. Set up the Lan to Lan VPN