Apart from the dynamic choice of connection outlined in the previous section, there are possible scenarios where certain TCP connections should always make use of the same DSL connection. Two cases are to be considered here:
- A server with a fixed IP address can only be contacted via a dedicated connection. All that is required for the selection here is the destination IP address.
- A server uses a protocol that requires a control channel and other channels for data transfer (e.g. FTP, H.323, PPTP). In establishing the data channels, servers accept only the same IP address as used by the control channel.