189
Glossary
Ap
pe
ndi
x
HOP
Number of routers that have passed through
to reach the remote party.
ITU-T
An abbreviation for International
Telecommunication Union,
Telecommunications.
MCU
An abbreviation for Multipoint Control
Unit. When connecting an MCU, a
multipoint connection is possible.
NTSC
An abbreviation for National TV Standards
Committee. NTSC is the television system
in use in Japan, the United States, etc.
It is not compatible with the PAL system.
PAL
An abbreviation for Phase Alternation Line.
PAL is the television system in use in
Europe, China, etc.
It is not compatible with the NTSC system.
ping
A command to check if the specified IP
address is connected to the IP network.
QoS
An abbreviation for Quality of Service. QoS
reserves a bandwidth for specific
communication in the network and
guarantees a given communication speed.
RTT (Round Trip Time)
Round-trip delay time. The time required for
a packet to reach a remote terminal and come
back.
SNMP
An abbreviation for Simple Network
Management Protocol. This protocol is for
management information between the
management station and the managed
terminals.
TOS
Inputting the information data in the TOS
field of the IP address allows the
communication system to judge the packet
transmission priority, etc. It also enables
change of path according to the types of
service (Delay or Size).
Traceroute
A command to trace the route across the IP
network to reach the connected IP address.
YPbPr
Component video that is transmitted with
three signal cables Y–, Pb and Pr.
