Agilent Technologies AuroraPresto, User Manual

Page: 246 / 266

Aurora Presto
- User Guide
Glossary-4 481801
A B C D E F G H I
J K
L N O P Q R S T U V W X
Y Z
BER
Bit Error Ratio/Rate - a measure of transmission
quality. This is represented as the number of bits
received in error during a transmission, divided by the
total number of bits transmitted in a specific interval.
It is usually shown as a negative exponent, (for
example, 10
-7
which means 1 out of 10
7
bits are in
error or 1 out of 10,000,000 bits are in error).
BERT
Bit Error Rate Test - usually performed with a Pseudo-
Random Bit Sequence (PRBS) payload, for the
measurement of transmission errors in data sent.
C
Cell
The unit of transmission in ATM - a fixed length
frame made up of 53 bytes (octets): a 5-byte header
and a 48-byte data payload.
Channel
This refers to the path for transmission of
information. It may be physical or logical.
CHAP
Challenge Handshake Authentication Protocol. This is
used during PPP sessions to verify User Names and
Passwords.
CO
Central Office. A central Switching or control centre
belonging to a PTT .
CPE
Customer Premise Equipment.
CRC
Cyclic Redundancy Check - an algorithm that
computes a numerical value based on the bits in a
block of data. This number is transmitted with the
data and the receiver uses this information and the
same algorithm to make sure that the data has been
delivered accurately by comparing the results of the
algorithm and the number received. If they are not the
same, an error in transmission has probably
happened.
481801-7.book Page 4 Thursday, May 23, 2002 10:46 AM