You can configure an idle timeout or a session timeout. The values you set are the default values for PPP B-RAS users. Attributes returned by RADIUS override these default settings on a per-user basis.

When you set the idle timeout, the PPP application on the router monitors both ingress (inbound) traffic and egress (outbound) traffic by default for the configured idle timeout period to determine whether to disconnect an inactive PPP session. If there is no activity in either direction on the interfaces for more than the configured idle timeout period, the router terminates the PPP session.

You can optionally configure the router to monitor only ingress traffic for the configured idle timeout period to determine session inactivity and subsequent disconnection of an inactive PPP session. Monitoring only ingress traffic for the idle timeout is useful for networks in which the PPP keepalive timer is disabled for wireless subscribers. Without the keepalive timer, the router cannot detect whether a wireless subscriber has been disconnected. Monitoring egress traffic does not indicate inactivity for wireless subscribers because egress traffic is always flowing. Enabling the router to monitor only ingress traffic enables you to selectively disconnect subscribers, including wireless subscribers, if no traffic is received for the configured idle timeout period.

The following sections describe timeout configuration:

• Limiting Active Subscribers
• AAA Failure Notification for RADIUS