You will basically have 2 options for WebAccess from outside of your network:
1/ Using buffalonas.com: Read the included User Manual
2/ Configure manually: If you have a dynamic IP address (which most people do), then you first need to set-up a "Host" which point to your dynamic IP Address, for example using www.Dyndns,org (free)
- Go to www.dyndns.org create one Account and Add a Host (free). Give it a name such as "your-ip-address.dyndns.org"
- Configure your DSL modem with this dyndns account. Also, give a static IP address to your NAS
- Configure your NAS, taken the Host Name from dyndns that you have registered.
- From your Router, Forward the Ports to your NAS IP address, as followings:
Port 9000 (Internal/External): Webaccess
Port 9090 (Internal/External): Bit torrent
Port 80: (Internal/External): Web-admin
Hope this helps