I think i can tell you exactly what the issue is,
I spent over 48 hours trying to sort this. didnt find anything on the net. also happen to be with 1and1
look at these settings:
IP security policies.....
which opens box...............Packet Filter Properties
near the bottom of the list there is a box ticked called :
'Close MSDE (TCP/UDP)' (I am asuming that MSDE = Microsoft SQL Database Engine?)
Select it
Press Edit...
which opens box............... Edit Rule Properties
Select (again) >> 'Close MSDE (TCP/UDP)'
Press Edit...
which opens box................IP filter List
then you will see a list of ports tcp 1433, udp 1434
{Thats our list of ports all down as a blocking rule.....}
I think what needs to be done from here is
either....
close that screen ..IP filter List
on the screen Edit Rule Properties
there is a tab Filter action, could just change that from Block to permit?
(maybe changing it to permit, will allow us to tick the "Block All" option again - which sounds safer, but the support guys said there is a know bug, so might not work)
or
on the Packet Filter Properties
just untick the the rule 'Close MSDE (TCP/UDP)'
you might have to untick the rule 'Block ALL' to get it running
its probably to late for this to help you, but hopefully will help someone else with the same issue.
Best Answer
(Second edit: if your network administrator on the server's LAN router side can't see any traffic coming to the router, then clearly the traffic is being blocked elsewhere: maybe in the client's LAN (is your client also behind a NAT?) or anywhere in between. Anyway I think VPN tunnel is the best approach to solve your problem)
(Edit: Keep in mind opening the database's port to the internet is not usually the best policy, better establish a VPN or at least filter the port to allow ONLY the ips who access it, like your webserver's, for example)
How did you bind the port? Is not a question of opening, it's about binding the router's incoming connections to port X (for example 1433), to port 1433 of the server lan's ip.
Besides there's the possibility any middle network is blocking the traffic before it reaches the router. Try changing the connection port in the router to, let's say 80 for example, IF it is free, or any other commonly non-blocked port.
Other probable reasons for your traffic being blocked may be traffic being blocked by type (traffic can be restricted by protocol in any/all ports, check also that) in the LAN's router or anywhere between the client outside the LAN and the router, in which case there's not much to do, but still you can set up a VPN tunnel to simulate a local connection, depending on your router's support for it (or you can also set it up on your server: check http://openvpn.net/).
Also check the server is not blocking connections coming from the router's ip address (sometimes it happens, but you should be able to see that on wireshark, I think)
Also http://progrium.com/localtunnel/ provides a free very easy to set up service to temporarily expose your server to the internet through a random generated subdomain link, it seems less safe, but still safer than opening/redirectig the port in the router without filtering...