LCP packets contain a con?¬?guration option ?¬?eld that allows devices to negotiate the
use of options, such as the maximum receive unit, compression of certain PPP ?¬?elds,
and the link authentication protocol. If a con?¬?guration option is not included in an LCP
packet, the default value for that con?¬?guration option is assumed.
2. Authentication phase (optional)
After the link has been established and the authentication protocol has been decided
on, the peer goes through the authentication phase. Authentication, if used, takes place
before the network layer protocol phase is begun.
PPP supports two authentication protocols: PAP and CHAP. Both of these protocols
are discussed in RFC 1334, ???PPP Authentication Protocols.??? However, RFC 1994,
???PPP Challenge Handshake Authentication Protocol (CHAP),??? renders RFC 1334
obsolete.
PPP Encapsulation
Link Setup and Control
Using LCP in PPP
Multiple Protocol
Encapsulations Using
NCPs in PPP
TCP/IP
Novell IPX
AppleTalk
Establishing a Point-to-Point WAN Connection with PPP 319
3. Network layer protocol phase
In this phase, the PPP devices send NCP packets to choose and con?¬?gure one or more
network layer protocols, such as IP.
Pages:
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474