2 cissp ® Official Study Guide Eighth Edition

Understand the difference between dedicated and nondedicated lines.
A dedicated line is 
always on and is reserved for a specific customer. Examples of dedicated lines include T1, 
T3, E1, E3, and cable modems. A nondedicated line requires a connection to be established 
before data transmission can occur. It can be used to connect with any remote system that 
uses the same type of nondedicated line. Standard modems, DSL, and ISDN are examples 
of nondedicated lines.
Know various issues related to remote access security.
Be familiar with remote access, 
dial-up connections, screen scrapers, virtual applications/desktops, and general telecom-
muting security concerns.
Know the various types of WAN technologies.
Know that most WAN technologies require 
a channel service unit/data service unit (CSU/DSU), sometimes called a WAN switch. There 
are many types of carrier networks and WAN connection technologies, such as X.25, Frame 
Relay, ATM, SMDS, SDH, and SONET. Some WAN connection technologies require addi-
tional specialized protocols to support various types of specialized systems or devices.
Understand the differences between PPP and SLIP.
The Point-to-Point Protocol (PPP) is 
an encapsulation protocol designed to support the transmission of IP traffic over dial-up 
or point-to-point links. PPP includes a wide range of communication services, including 
assignment and management of IP addresses, management of synchronous communica-
tions, standardized encapsulation, multiplexing, link configuration, link quality testing, 
error detection, and feature or option negotiation (such as compression). PPP was originally 
designed to support CHAP and PAP for authentication. However, recent versions of PPP 
also support MS-CHAP, EAP, and SPAP. PPP replaced Serial Line Internet Protocol (SLIP). 
SLIP offered no authentication, supported only half-duplex communications, had no error-
detection capabilities, and required manual link establishment and teardown.