Section: Security Operation Adimnistration
Explanation/Reference:
The main issue with media reuse is data remanence, where residual information still resides on a media that has been erased. Degaussing, purging and destruction are ways to handle media that contains data that is no longer needed or used.
Source: WALLHOFF, John, CBK#10 Physical Security (CISSP Study Guide), April 2002 (page 5).

Explanation/Reference:
ATM is an example of a fast packet-switching network that can be used for either data, voice or video, but packets are of fixed size.
Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter
7: Telecommunications and Network Security (page 455).

Section: Risk, Response and Recovery
Explanation/Reference:
It's interesting to note that the steps to resume normal processing operations will be different than the steps in the recovery plan; that is, the least critical work should be brought back first to the primary site.
My explanation:
at the point where the primary site is ready to receive operations again, less critical systems should be brought back first because one has to make sure that everything will be running smoothly at the primary site before returning critical systems, which are already operating normally at the recovery site.
This will limit the possible interruption of processing to a minimum for most critical systems, thus making it the best option.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 8: Business Continuity Planning and Disaster Recovery Planning (page 291).

Section: Access Control
Explanation/Reference:
Authentication is verification that the user's claimed identity is valid and is usually implemented through a user password at log-on time.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 36.

The International Standards Organization / Open Systems Interconnection
(ISO/OSI) Layers and Characteristics Standard model for network communications enables
dissimilar networks to communicate, Defines 7 protocol layers (a.k.a. protocol stack) Each
layer on one workstation communicates with its respective layer on another workstation
using protocols (i.e. agreed-upon communication formats) "Mapping" each protocol to the
model is useful for comparing protocols.
Mnemonics: Please Do Not Throw Sausage Pizza Away (bottom to top layer)
All People Seem To Need Data Processing (top to bottom layer).
Source: STEINER, Kurt, Telecommunications and Network Security, Version 1, May 2002,
CISSP Open Study Group (Domain Leader: skottikus), Page 12.