Outbound Connections Scenario

Outbound communications begin when a user on one endpoint host initiates an activity involving the peer host on the other end of the PPP link. The following activities take place when a user types an rcp command to copy a file from a host on the other side of the link.

1. rcp sends the data through the levels of the TCP/IP protocol stack.

2. A virtual network interface (ipdn or ipdptpn) receives the data in the form of IP packets.

3. The interface sends the aspppd link manager a connection request that initiates an outbound connection.

4. The link manager then:

   1. Verifies that the connection request corresponds to a configured path in the /etc/asppp.cf configuration file.

   2. Consults the UUCP database files (/etc/uucp/Systems, /etc/uucp/Devices, and /etc/uucp/Dialers) for specific information about the modem and destination system.

   3. Places a phone call to the destination host or attaches to the appropriate hardwired serial line.

5. The physical link to the peer host is established.

6. The link manager configures and initiates PPP.

7. The data-link layer is established, and the PPP modules on the peer host start communicating.

8. The link manager enables IP over the link.

The link manager then monitors the connection until an event, such as an idle timeout, line disconnect, or error condition, occurs. When any of these events occurs, the link manager disconnects from the peer host and returns to the idle state.