Руководство Пользователя для Netopia 2e-h-w

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How Your Cayman 2E-H-W Works
Cayman 2E-H-W User’s Guide
C-6
November 2000
 Each phase is described separately below. 
Link Establishment
The manner in which a PPP link is opened depends on whether the 
router's serial or Ethernet port is configured as a dial-in, dial-out, or 
dedicated PPP interface:
Dial-in – If a port is configured as a dial-in interface, the router 
sends an initialization string to the modem when it is turned on 
to prepare it to accept calls. When the local modem receives an 
incoming call and negotiates the serial connection settings, the 
serial connection is established and the link peers begin 
negotiating the link configuration.
Dial-out – If a port is configured as a dial-out interface, the router 
opens a PPP link when an internal Network Protocol routes a 
packet out the PPP interface. If PPP determines that the serial 
connection is not open, the router passes a telephone number 
and modem configuration information to the modem, which 
calls the modem connected to the remote peer. When the two 
modems establish a connection, the two peers begin negotiating 
the link configuration.
A port configured as both a dial-in and dial-out interface will 
open a link if it receives a packet from either direction. 
Dedicated – If a port is configured as a dedicated interface, the 
router maintains a PPP link at all times. PPP over Ethernet links 
are dedicated links.
Link Configuration
Link Control Protocol (LCP) configuration options allow 
modification to the standard characteristics of a PPP link to be 
negotiated. Negotiable options include settings for the maximum 
receive unit (MRU), asynchronous control character mapping, and 
link authentication. If a configuration option is not negotiated (that 
is, if a Configure-Request packet does not include a value for a 
particular option), the default value for that option is assumed.