Руководство Пользователя для Netopia 2e-h-w

Скачать
Страница из 170
Cayman 2E-H-W User’s Guide
How Your Cayman 2E-H-W Works
November 2000
C-5
About PPP
The Point-to-Point Protocol (PPP) is a set of network protocols that 
enables you to connect TCP/IP hosts and networks over a serial 
telephone connection (applicable to older versions of the Cayman 
2E-H-W) or an Ethernet (xDSL or cable modem) connection. 
Extensions to the PPP protocol suite enable a PPP link to support 
other network protocols, including IPX, AppleTalk, and DECnet. The 
nodes at each end of a PPP link are referred to as peers. Unlike 
client-server networks, where one device is responsible for 
providing services to another, peer-to-peer networks function as 
equals, providing services to one another as needed.
How PPP Works
PPP provides a standard method of encapsulating network protocol 
information over point-to-point links. PPP also defines a Link Control 
Protocol (LCP), which provides for link configuration, peer 
authentication, and link quality monitoring. Finally, PPP includes 
several Network Control Protocols (NCPs), which establish how 
datagrams for a specific higher-level protocol using PPP as a data link 
should be encapsulated. Network control protocols establish and 
configure different network-layer protocols, such as TCP/IP. PPP 
encapsulation provides for transmission of different network-layer 
protocols simultaneously over the same link. 
Phases of a PPP 
Link
When one PPP peer opens a link to another peer, the PPP link moves 
through several phases:
Link establishment 
Link configuration
Authentication 
Network configuration
Link up 
Link termination