Avaya a500 用户指南
Cajun A500 ATM Switch Overview
Cajun A500 ATM Switch User Guide
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Initially, the PPP task configures the channel for dialin mode and starts the PPP network
interface; this creates and starts the PPP daemon. The PPP daemon waits on
initialization, send, receive, and control events. The serial port and modem are initialized
through the PPP daemon. The PPP task has the following duties when set up:
U Checks message queue for a trap message - If there is a trap message, it saves
the information in a private log. If the trap is the first one in, the log starts a hold
trap message timer.If the log is almost full (ten events) then change PPP network
configuration to dialout and send trap. After last trap is sent out the PPP channel
waits five seconds and then shuts down the dialout connection and returns to
waiting for dialin connection.
U Checks to see if hold trap message timer has expired - If yes, then configure
the channel for dial out and send the trap.After the last trap is sent out the PPP
channel, wait five seconds and then shuts down the dialout connection and goes
back to waiting for dialin connection.
U Checks the link status - If link was up and then goes down again, reset the
modem and start waiting for dialin connect again.
The PPP task does not break down a dialin connection enricher to send out a trap
in the above cases. Instead it waits for dialin link to be disconnected.
Authentication Configuration
PPP defines a Link Control Protocol, which enables negotiation of an Authentication
Protocol for authenticating its peer before allowing Network Layer protocols to transmit
over the link. Authentication configuration options are:
U Password Authentication Protocol (PAP)
U Challenge Handshake Authentication Protocol (CHAP)
The IP Control Protocol (IPCP) is negotiated last. After this step completes, the entire link
opens so that applications can begin passing data. These authentication protocols are
intended for use primarily by hosts and routers that connect to a PPP network server via
switched circuits or dialup lines, but might be applied to dedicated links as well. The
server can use the identification of the connecting host or router in the selection of
options for network layer negotiations.