GLOSSARY 437
congestion The result of increased network use on a LAN segment. Standard
network partitioning practices must be invoked to reduce bottlenecks
and maximize throughput speeds on the segment.
contention The method used to resolve which users gain access to crowded
bandwidth.
CO Central Office. A telephony term for the telephone company site that
houses the PSTN switching equipment.
CoS Class of Service. A collection of calling permissions that are assigned to
individual users and govern the times and types of calls these users can
make.
CPE Customer Premises Equipment. Telecommunications equipment,
including PBXs and wiring, that is located in a user’s premises.
CSU Channel Service Unit. Data transmission equipment to repeat the signal
from the carrier and link to CPE. Vendors add value to CSUs by adding
performance monitoring and management features.
CTI Computer Telephony Integration. A generic name for the technology that
connects computers and telephone systems through software
applications.
data compression A method of reducing the amount of data to be transmitted by reducing
the number of bits needed to represent the information.
delayed ringing Prevents a telephone on a shared line from ringing until the incoming call
has rung on other telephones a set number of times.
delayed ringing
pattern
The definition for the order in which telephones ring and how many
times each telephone rings.
demand priority
access
A method for supporting time-sensitive applications such as video and
multimedia as part of the proposed 100BASE-VG standard offering
l00Mbit/s over voice-grade UTP cable.
DHCP Dynamic Host Configuration Protocol. A method by which devices are
assigned temporary, renewable IP addresses by a server when the devices
become active on the network.
DID/DDI Direct Inward Dial/Direct Dialing Inward. A feature that allows outside
calls to reach an internal extension without going to an operator or
Automated Attendant.