To use FILESTREAM in a firewall-protected environment, both the client and server must be able to resolve DNS names to the server that contains the FILESTREAM files. FILESTREAM requires the Windows file-sharing ports 139 and 445 to be open.
To open the Windows file-sharing ports on a computer that is running Windows 7
In Control Panel, open Windows Firewall.
In the left pane, click Advanced settings. If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
In the Windows Firewall with Advanced Security dialog box, in the left pane, click Inbound Rules, and then, in the right pane, click New Rule.
Follow the instructions in the New Inbound Rule wizard to add TCP port 139.
Repeat the previous step to add TCP port 445.
Close the Windows Firewall with Advanced Security dialog box.