Demand-Dial Routing

Using Multilink and BAP

Multilink and Bandwidth Allocation Protocol (BAP) can be used with demand-dial routing to automatically add physical connections to a Multilink PPP connection when network traffic increases and remove physical connections when the network traffic decreases.

To create a Multilink or BAP demand-dial connection

In the Routing and Remote Access snap-in, double-click Routing Interfaces.
Right-click Routing Interfaces, point to New, and then click Demand-dial interface.
In the Demand-Dial Wizard, select the modem that you want to use for the first physical connection.
Right-click the demand-dial interface, and then click Properties.
On the General tab under Connect using, select the modems or ports that you want to use for the connection and the order in which you want to use them.
If each of the separate physical connections calls a different number, then clear All devices call the same numbers. The number to call is negotiated by BAP at the time the connection is required.
On the Options tab under Multiple devices, click Dial devices only as needed.
Click Configure to specify when a new physical connection is made and when an existing physical connection is dropped. The Automatic Dialing and Automatic Hanging Up dialog box is shown in Figure 6.3.
Under Automatic dialing, select the appropriate conditions under which a new line is dialed. The default setting is two minutes at 75 percent or more capacity of the exiting MP connection.

Under Automatic hangup, select the appropriate conditions under which a line is hung up. The default setting is two minutes at 10 percent or less capacity of the line.

Enlarge figure

Figure 6.3 Automatic Dialing and Automatic Hanging Up Dialog Box

Note

If a link within the multilink bundle is dropped when using multilink without BAP, then it does not automatically reconnect. To force a reconnection of dropped links in a multilink bundle, use BAP and configure your links for settings that always cause the links to be initialized when the demand-dial connection is created and always reinitialized when the line is dropped. For example, set automatic dialing conditions for Activity at least to 1% and Duration at least to 3 seconds.