Compatible Systems 5.4 manual WAN Link Protocols, Link Type, Failover Type

156 Chapter 10 - WAN Link Protocols

>Link Type

This pull-down menu determines how the router will maintain the WAN link, and sets the low-level communications protocol which will be used on the line connected to this interface.

•If On Demand PPP Link is selected, the router will treat the line connected to this interface as an intermittent “on-demand” connection which may require dialing commands to be issued. The router will use the Point-to-Point protocol to establish communications with the system at the other end of the line. Whether a connection can be initiated by this router, another router (or remote node client), or both, can be set using the Allow Dial Out and Allow Dial In checkboxes (as explained later in this chapter).

•If Dedicated PPP Link is selected, the router will treat the line connected to this interface as a connection which is always available regardless of traffic activity. The router will use the Point-to-Point protocol to establish communications with the system at the other end of the line.

•If Frame Relay Link is selected, the router will treat the line connected to this interface as a connection which is available regardless of traffic activity. The router will use the Frame Relay protocol to establish communications with the system (typically a Frame Relay switch) at the other end of the line.

ϖNote: For On Demand PPP Link operation over RS-232C DIN-8 inter- faces, Compatible Systems routers require that your communications device (modem, CSU/DSU, TA, etc.) be set to raise the DCD (data carrier detect) and/or DSR (data set ready) line when a connection is established, and drop it when the connection is terminated.

ϖNote: If an interface is set to On Demand PPP Link, there are certain maintenance packets for each protocol (IP, IPX, etc.) which will not cause an inactive connection to be dialed. This is a security measure that keeps intruders out and allows on-demand links to be useful.

ϖNote: The push buttons at the bottom of this dialog box will change depending on the choice you make for this pulldown.

Failover Type

WAN ports can be set to divert their traffic to a secondary port (known as “failing over”) if a line problem is detected. This pull-down menu determines the failover mode for this port.

Ports set for PPP operation will fail over if the PPP echo protocol determines that the line is down. Ports set for Frame Relay operation will fail over if the