INSY 3303 Exam 2 Review
Access Layer
·
The layer that provides network access.
Ex. Local Area Network (LAN)
ACK (acknowledgement message)
·
the part of the ARQ algorithm that lets the sender know that the
package has been correctly received without errors.
Address Resolution
·
the process of translating the application layer address (or
server name) of the destination into a network layer address, and in turn
translate that into a data link layer address
Server Name Resolution
·
translation of application layer addresses into network layer
addresses and is done using the Domain Name Service (DNS) (Ex. Website URL to
IP address)
ARP (Address Resolution Protocol)
·
A core protocol in the TCP/IP suite that belongs in the Network
layer of the OSI model. ARP obtains the MAC (physical) address of a host, or
node, and then creates a local database that maps the MAC address to the host's
IP (logical) address.
ARQ (Automatic Repeat reQuest)
·
when a receiver that detects an error simply asks the sender to
retransmit the message until it is received without error.
Asychronous Transmission
·
often referred to as start-stop transmission because the
transmitting computer can transmit a character whenever it is convenient, and
the receiving computer will accept that character.
Baselining
·
when designers must review the list of applications that will
use the network and identify the location of each, and the information is added
to the emerging network documentation.
BGP (Border Gateway Protocol)
·
a dynamic distance vector exterior routing protocol used on the
Internet to exchange routing information between autonomous systems—that is,
large sections of the Internet.
What are the disadvantages to using BGP?
·
It is large, complex, and often hard to administer.
Bottleneck
·
a circuit that is filled almost to its capacity and is the
critical point that determines whether users get good or bad response times.
Building-Block Network Design Process
·
when networks that use a few standard components throughout the
network are cheaper in the long run than networks that use a variety of
different components on different parts of the network.
What is the goal of the Building-Block Network Design Process?
·
a simpler design process and a more easily managed network built
with a smaller range of components.
What are the three steps that are performed in Building-Block
Network Design Process?
·
Needs Analysis
2. Technology Design
3. Cost Assessment
What is a needs analysis?
·
the process of understanding the fundamental current and future
network needs of the various users, departments, and applications.
What is technology design?
·
examining the available technologies and assessing which options
will meet the users' needs.
What is a cost assessment?
·
when the relative costs of the technologies are considered.
Circuit Loading
·
the amount of data transmitted on a circuit
Common Carrier
·
private companies such as AT&T, Bell Canada, Sprint, and
BellSouth that provide communication services to the public.
Core Layer
·
The third network architecture component and is also known as
the campus backbone. This layer connects all the buildings on one campus.
Data Center
·
The fourth network architecture component and it contains the
organization's servers.
DHCP (Dynamic Host Configuration Protocol)
·
A network service that provides automatic assignment of IP
addresses and other TCP /IP configuration information.
Distribution Layer
·
The second network architecture also called the building
backbone network. This layer distributes network traffic to and from LANs.
DNS (Domain Name Service)
·
a server name resolution system that translates an internet
address (application layer address) into an IP address (network layer address).
name server
·
A series of computers throughout the internet that provides DNS
services. These servers contain address databases and stores thousands of
internet addresses and their corresponding IP addresses.
eCommerce Edge
·
This is the final network architecture component. It is a
special LAN with a group of severs that enables electronic data exchange
between the organization and the external entities with which it does business
with.
EIGRP (Enhanced Interior Gateway Routing Protocol)
·
a dynamic hybrid interior routing protocol developed by Cisco
that records information about a route's transmission capacity, delay, reliability,
and load.
What makes EIGRP unique?
·
Computers or routers store their own routing tables as well as
the routing tables for all of their neighbors so they have a more accurate
understanding of the network.
Enterprise Edge
·
Made up of the last three components of the network
architecture. It is the parts of the network that are at the edge of an
enterprise campus and connect that campus to the rest of the world.
Error Control.
·
Network errors, such as those that occur during transmission,
are controlled by the network hardware and software.
What are the sources of errors?
-
Line Noise
- White Noise
- Impulse Noise
- Cross talk
- Echoes
- Attenuation
- Intermodulation Noise
Error Detection
·
sending extra data with each message. These error-detection data
are added to each message by the data link layer of the sender on the basis of
some mathematical calculations performed on the message
What are the different error-detection methods?
·
-Parity checking
-Checksum
-Cyclic Redundancy Check (CRC)
What is parity checking?
·
An additional bit is added to each byte in the message that can
detect if the hardware loses a bit during the internal movement of a byte.
What is a checksum?
·
when a byte is added to the end of the message and is calculated
by adding the decimal value of each character in the message, dividing the sum
by 255, and using the remainder as the checksum.
What is Cyclic Redundancy Check (CRC)?
·
A mathematical algorithm that is executed on a data string by
both the sender and the receiver of the data string. If the calculated values
match, the receiver can conclude that the data string was not corrupted during
transmission.
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