Avaya Configuring PPP Services Manual do Utilizador descarregar pdf (Página 31)

PPP Concepts

117360-A Rev. A 2-5

The protocol that you selected when you ﬁrst enabled PPP on the circuit is

enabled by default. You can enable a different protocol by editing PPP protocol

parameters, as described in Chapter 3.

Transparent/Translation Bridge and Source Route Bridge are other routing media

that you can enable over any PPP interface. The PPP bridge accepts incoming

trafﬁc from any media (Ethernet, FDDI, token ring) and forwards data

transparently (or translates when necessary).

Initializing a PPP Interface

PPP creates an interface between peer routers to allow them to exchange data. The

routers initialize the interface in three phases:

1. Establishing the PPP link

2. Authenticating the link (optional for leased lines)

3. Negotiating network layer protocols

The following sections describe each phase.

Establishing the PPP Link

PPP’s Link Control Protocol (LCP) helps establish a link. LCP generates three

types of packets:

• Link conﬁguration packets, including conﬁgure-request, conﬁgure-ACK,

conﬁgure-NAK, and conﬁgure-reject packets

• Link termination packets, including terminate-request and terminate-ACK

packets

• Link maintenance packets, including code-reject, protocol-reject,

echo-request, and echo-reply packets

When two routers initialize a PPP dialogue, each of them sends a

conﬁgure-request packet to the other (peer) router. Each conﬁgure-request packet

contains a list of LCP options and corresponding values that the sending router

uses to deﬁne its end of the link.

1 2 ... 26 27 28 29 30 31 32 33 34 35 36 ... 139 140

Sem comentários

Avaya Configuring PPP Services Manual do Utilizador Página 31