Explanation:
In computer networks, bandwidth is often used as a synonym for data transfer rate – it is the amount of data that can be carried from one point to another in a given time period (usually a second).
This kind of bandwidth is usually expressed in bits (of data) per second (bps). Occasionally, it’s expressed as bytes per second (Bps). A modem that works at 57,600 bps has twice the bandwidth of a modem that works at 28,800 bps. In general, a link with a high bandwidth is one that may be able to carry enough information to sustain the succession of images in a video presentation.
It should be remembered that a real communications path usually consists of a succession of links, each with its own bandwidth. If one of these is much slower than the rest, it is said to be a bandwidth bottleneck.
For your exam you should know below information about Network performance:
Network performance refers to measurement of service quality of a telecommunications product as seen by the customer.
The following list gives examples of network performance measures for a circuit-switched network and one type of packet-switched network (ATM):
Circuit-switched networks: In circuit switched networks, network performance is synonymous with the grade of service. The number of rejected calls is a measure of how well the network is performing under heavy traffic loads. Other types of performance measures can include noise, echo and so on.
ATM: In an Asynchronous Transfer Mode (ATM) network, performance can be measured by line rate, quality of service (QoS), data throughput, connect time, stability, technology, modulation technique and modem enhancements.
There are many different ways to measure the performance of a network, as each network is different in nature and design. Performance can also be modeled instead of measured; one example of this is using state transition diagrams to model queuing performance in a circuit-switched network. These diagrams allow the network planner to analyze how the network will perform in each state, ensuring that the network will be optimally designed.
The following measures are often considered important:
Bandwidth – Bandwidth is commonly measured in bits/second is the maximum rate that information can be transferred
Throughput – Throughput is the actual rate that information is transferred
Latency – Latency is the delay between the sender and the receiver decoding it, this is mainly a function of the signals travel time, and processing time at any nodes the information traverses
Jitter – Jitter is the variation in the time of arrival at the receiver of the information
Error Rate – Error rate is the number of corrupted bits expressed as a percentage or fraction of the total sen
The following answers are incorrect:
Throughput – Throughput is the actual rate that information is transferred
Latency – Latency is the delay between the sender and the receiver decoding it, this is mainly a function of the signals travel time, and processing time at any nodes the information traverses
Jitter – Jitter is the variation in the time of arrival at the receiver of the information
Reference:
CISA review manual 2014 page number 275