A demand-dial routing scenario

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

A demand-dial routing scenario

The following illustration shows a router configuration that uses demand-dialing.

Networks A and B are geographically separated and, for the amount of traffic that is transferred between the networks, a leased WAN link is not economical. Router 1 and Router 2 can connect over an analog phone line by using modems on both ends (or another type of connectivity, such as ISDN). When a computer on Network A initiates communication with a computer on Network B, Router 1 establishes a phone connection with Router 2. The modem connection is maintained as long as there are packets going back and forth. When the connection is idle, Router 1 hangs up to reduce connection costs.

For a detailed explanation of what happens during a demand-dial connection, see Understanding Demand-Dial Routing.