From the look of your new connection string, it looks like you're hosting it somewhere on the internet.
Microsoft SQL Server requires certain ports to be opened to communicate over a firewall. The default SQL Server port is 1433, and client ports are assigned a random value between 1024 and 5000.
Now if this server is on the internet: *don't open those ports*, unless you know what you are doing.
Please read Encrypting Connections to SQL Server
] - or even better: Expose you datalayer as a web-service, and use SSL to communicate with that web service.