Installing and Administering PPP

164 Glossary
Glossary
International Standards
Organization (ISO):
organization that publishes a
broad range of international
standards for industry, including a
large number that are identical or
nearly identical to CCITT
standards.
Internet Protocol (IP): the
layer of the Internet family of
protocols that is responsible for
packet routing and datagram
fragmentation and reassembly.
Internet Protocol Control
Protocol (IPCP): the Network
Control Protocol for the Internet
Protocol.
IP: see Internet Protocol.
IPCP: see Internet Protocol
Control Protocol.
ISO: see International Standards
Organization.
LCP: see Link Control Protocol.
Link Control Protocol
(LCP): the protocol that
establishes, configures, and tests
the data link connection.
Link Quality Monitoring
(LQM): a negotiable feature of
LCP that allows a PPP
implementation to determine
when and how often the link is
losing data. If both ends of a PPP
link agree to perform LQM, they
will periodically send Link Quality
Report messages to their peer
containing various sequence
numbers, state variables, and byte
and packet counts. This
information is then used to
measure how reliable the
connection is, and can be used to
decide when to shut down the
connection down and perhaps try
again.
Link Quality Report (LQR): an
LCP message sent after
successfully negotiating the LQM
option. The LQR contains various
state variables, packet counts, and
byte counts.
LQM: see Link Quality
Monitoring.
LQR: see Link Quality Report.
Magic Number: a 32-bit random
number, unique to each end of each
PPP link, used to determine if the
link is looped back. If a PPP
implementation discovers that its
peer has the same Magic Number,
it will strongly suspect that it is
talking to itself.