Lucent Technologies SLC ConnectReach User & Service Manual page 521

Glossary 363-208-050
CLOC — Loopback - toward customer side at slave unit.
CO — Central office.
cpm0-1 — Normal interface to the local Ethernet network; used in Interface statistics.
CRC — Cyclic Redundancy Check. Error detection technique that derives a binary number by reading an
incoming block of data and compares it with a number transmitted with the data.
CREM — Loopback - toward customer side at master unit.
CSMA/CD — Carrier Sense Multiple Access Collision Detect. Media-access mechanism wherein devices
ready to transmit data first check the channel for a carrier. If no carrier is sensed for a specific period of
time, a device can transmit. If two devices transmit at once, a collision occurs and is detected by all
colliding devices. This collision subsequently delays retransmissions from those devices for some random
length of time. CSMA/CD access is used by Ethernet and IEEE 802.3.
CSS — Counted Slip Seconds. Used in T1 line statistics.
CSU — Channel Service Unit. A CSU terminates a T1 digital circuit at the customer site. The CSU
performs certain line-conditioning functions, ensures network compliance with Federal Communications
Commission (FCC) rules, and responds to loopback commands. The CSU also ensures proper ones
density in transmitted bit stream and performs bipolar-violation correction.
D
D4 — A framing format that uses a 12-bit pattern repeating sequence for the location of the framing bits.
Also referred to as Superframe (SF) format.
dB — Decibel, a unit of measure of relative power, expressed as the ratio of two values. dB = 10 log P1
P2, where P1 and P2 are the power levels in watts.
®
Delay Dial — A type of trunk signaling for incoming and outgoing calls. With this signaling, the SLC
™
ConnectReach system sends an off-hook pulse until it is ready to receive digits.
DHCP — Dynamic Host Configuration Protocol. Acting as a DHCP server, the SLC ConnectReach system
dynamically assigns IP addresses and other configuration parameters needed by personal computers
(PCs) or workstations to connect to the Internet and perform common network functions.
Dial Supervision — The method for originating address digit transmission such as wink start and delay
start.
DID — Direct Inward Dial. A DID trunk passes the last two to four digits of a phone number to the PBX or
hybrid phone system. At this point the digits are either modified by the phone system or used as is to
connect to an internal extension. This allows outside calls to reach an internal extension directly by dialing
a seven-digit number.
GL-3
Issue 4 June 2002