(1) Identifying Network Architectures The following lab reviews
your knowledge of the different types of network architectures. The
following table summarizes the different network architectures.
Completes the table (add lines if necessary).Architecture Token
Ring
Topology
Topology Ring Topology Star-using Token Ring repeater hubs
b) Using several MAUs (Multi station Access Unit) connected to
each other.Using a single MAU (Multi station Access Unit)
Cabling Shielded Twisted-Pair (STP) cable DB9 connector A unique
square connector called the IBM data connector. Unshielded
twisted-pair (UTP) cable with RJ-45 connectors.
Access methods It used a special three-byte frame called a token
that travels around the ring. Token-possession grants the possessor
permission to transmit on the medium. Token ring frames travel
completely around the loop.
The data transmission process goes as follows: Empty information
frames are continuously circulated on the ring. When a computer has
a message to send, it seizes the token. The computer will then be
able to send the frame. The frame is then examined by each
successive workstation. The workstation that identifies itself to
be the destination for the message copies it from the frame and
changes the token back to 0. When the frame gets back to the
originator, it sees that the token has been changed to 0 and that
the message has been copied and received. It removes the message
from the frame. The frame continues to circulate as an "empty"
frame, ready to be taken by a workstation when it has a message to
send.
Speed Transfer speed rates 4mbps and 16 mbps.
Architecture 10Base2
Topology
Topology Bus
Cabling Thin coaxial cable Cables in the 10Base-2 system connect
with BNC connectors. The Network Interface Card (NIC) in a computer
requires a T-connector Repeater Transceiver 50 Ohm Terminator
Thinnet Tap 4 Port Expansion Box Thick Ethernet Trunk Coax Cable
RG-58 cable
Access methods Typically, devices use Ethernet network interface
cards (NICs) with built-in BNC transceivers, so connections can be
made directly to the Thin Coaxial cable
Speed Transfer speed rates 10 mbps
Architecture 10BaseT
Topology
Topology Star, using either simple repeater hubs or Ethernet
switches
Cabling Uses a Unshielded Twisted-Pair Cable 10Base-T system
connect with RJ-45 connectors Switch Router Bridge
Access methods 10BASE-T and UTP segments can coexist on the same
network via a transceiver and transceiver cable or converter when
each hub is attached to a common segmen. Each node on the network
has its own cable run back to a common hub, and each of these cable
runs may be up to 100 meters (330 feet) in length.
Speed Transfer speed 10Mbps
Architecture 10Base5
Topology
Topology Bus
Cabling RG-8 Thick Coaxial Cable AUI (Attachment Unit Interface)
Connector Transceiver MAU (Multi station access unit) N
connector
Access methods Devices attach to the backbone via transceivers.
The minimum distance between transceivers is 2.5 metres.
Speed Transfer speed 10 mbps
Architecture 100BaseT
Topology
Topology Star, using either simple repeater hubs or Ethernet
switches
Cabling Unshielded twisted-pair (UTP) RJ45-connector Hub Switch
Router
Access methods all cables are attached to a hub
Speed Transfer Speed 100Mbps
Architecture100BaseSX
Topology
Cabling Unshielded Twisted Pair Cable Switch Hub
Access methods 100BASE-TX is the predominant form of Fast
Ethernet, and runs over two wire-pairs inside a category 5 or above
cable. Like 10BASE-T the active pairs in a standard connection are
terminated on pins 1, 2, 3 and 6. 100BASE-SX uses low cost short
wavelength (850nm) optics. The point-to-point distance of
100BASE-SX is 300 meters over supported fibre types, more than
adequate for desktop applications. 100BASE-SX leaves the choice of
connector to the user, allowing any connector that meets the
minimum specified performance.
Speed Transfer speed 10 Mbps copper or fiber to 100 Mbps
(2) Identifying Network TopologiesList the networking topologies
below and complete the table;(Add lines if necessary)Topology
NameIllustrations /pictureDescriptionAdvantagesDisadvantages
Star
A star topology is a topology for a Local Area Network (LAN) in
which all nodes are individually connected to a central connection
point, like a hub or a switch. A star takes more cable than e.g. a
bus, but the benefit is that if a cable fails, only one node will
be brought down.
Nodes can be connected and removed at any time without affecting
the whole system directly.
Any damage to the connection between node & hub will not
affect the overall system.
The damage can be detected more easily and quickly
The installation process and connectivity is easy. Requires a
lot of cable and the installation costs is higher.
If the hub is broken, all the nodes cannot function in a network
system.
The use of hub, a router or a switch as central device increases
the overall cost of the network.
Too much dependency on central device has its own drawbacks. If
it fails whole network goes down.
Topology NameIllustrations
/pictureDescriptionAdvantagesDisadvantages
Bus
A bus topology is a topology for a Local Area Network (LAN) in
which all the nodes are connected to a single cable. The cable to
which the nodes connect is called a backbone. If the backbone is
broken, the entire segment fails. Bus topologies are relatively
easy to install and dont require much cabling compared to the
alternatives. It is easy to set-up and extend bus network.
Cable length required for this topology is the least compared to
other networks.
Bus topology costs very less.
Linear Bus network is mostly used in small networks. Good for
LAN. There is a limit on central cable length and number of nodes
that can be connected
Maintenance costs can get higher with time.
It is not suitable for networks with heavy traffic.
It is difficult to detect and troubleshoot fault at individual
station
Ring
A ring topology is a topology for a Local Area Network (LAN) in
which every device has exactly two neighbours for communication
purposes. Typically, all messages travel through a ring in the same
direction. A failure in any cable or device breaks the loop and
will take down the entire segment. This type of network topology is
very organized. Each node gets to send the data when it receives an
empty token. This helps to reduces chances of collision. Also in
ring topology all the traffic flows in only one direction at very
high speed.- Even when the load on the network increases, its
performance is better than Bus topology.-There is no need for
network server to control the connectivity between
workstations.Each packet of data must pass through all the
computers between source and destination. This makes it slower than
Star topology.
If one workstation or port goes down, the entire network gets
affected.
Network is highly dependent on the wire which connects different
components.
MAHUs and network cards are expensive as compared to Ethernet
cards and hubs.
Topology NameIllustrations
/pictureDescriptionAdvantagesDisadvantages
MeshA Mesh topology provides each device with a point-to-point
connection to every other device in the network.
Mesh topologies use routers to determine the best path. Mesh
networks provide redundancy, in the event of a link failure, meshed
networks enable data to be routed through any other site connected
to the network. Because each device has a point-to-point connection
to every other device, mesh topologies are the most expensive and
difficult to maintain.Data can be transmitted from different
devices simultaneously. This topology can withstand high
traffic.
Even if one of the components fails there is always an
alternative present. So data transfer doesnt get affected.
Expansion and modification in topology can be done without
disrupting other nodes. There are high chances of redundancy in
many of the network connections.
Overall cost of this network is way too high as compared to
other network topologies.
Set-up and maintenance of this topology is very difficult. Even
administration of the network is tough
TreeA tree topology combines characteristics of linear bus and
star topologies. It consists of groups of star-configured
workstations connected to a linear bus backbone cable.
Tree topologies allow for the expansion of an existing network,
and enable schools to configure a network to meet their needs.It is
an extension of Star and bus Topologies, so in networks where these
topologies cant be implemented individually for reasons related to
scalability, tree topology is the best alternative
Expansion of Network is possible and easy.
Error detection and correction is easy.
If one segment is damaged, other segments are not
affected.Because of its basic structure, tree topology, relies
heavily on the main bus cable, if it breaks whole network is
crippled.
As more and more nodes and segments are added, the maintenance
becomes difficult.
Scalability of the network depends on the type of cable
used.
(3) Identifying Network equipment.List the networking equipment
for the following applications areas;
A- Cabling EquipmentEquipment NameIllustrations
/pictureDescription Usage
Coaxial cable
A coaxial cable is a type of shielded and insulated copper cable
that is used in computer networks and to deliver cable TV services
to end users. It was first commercially implemented in the early
1940s and is used for both baseband and broadband data
communication services.Coaxial cable is also known as coax, which
is derived from the geometric axis created between a shield and
insulator.
Coaxial cable is common used to connect home video equipment, in
ham radio setup and in measurement electronics. Common for
implement computer network, in particular Ethernet. Long distance
coaxial cable was used in 20th century to connect radio networks,
television network and Long Distance Telephone network.
Twisted Pair cable
Twisted pair cable is a type of cabling that is used for
telephone communications and most modern Ethernet networks. Its
made up of two insulated copper wire, typically twisted around each
other in a continuous spiral. There are several categories
involving twister pair cable. Every category has its own attraction
and limitation of application. Namely, there is Category 1 to
Category 6. For example, Category 1 is used for telephone
communication and not suitable for transmitting data.
UTP
UTP cable is a medium that is composed of pairs of wires.UTP
cable is used in a variety of networks. Each of the eight
individual copper wires in UTP cable \is covered by an insulating
material. In addition, the wires in each pair are twisted around
each other. UTP cable relies solely on the cancellation effect
produced by the twisted wire pairs to limit signal degradation
caused by electromagnetic interference (EMI) and radio frequency
interference (RFI).Uses twisted pair to cancel out electromagnetic
interference and cross talk by two wires. Most common example is
CAT 5 cable. When used as a networking medium, UTP cable has four
pairs of either 22- or 24-gauge copper wire. UTP used as a
networking medium has an impedance of 100 ohms; this differentiates
it from other types of twisted-pair wiring such as that used for
telephone wiring, which has impedance of 600 ohms.
Cat 5e cable
Category 5 Enhanced. This Cat 5e network cablings used as a
cabling infrastructure for 10 BASE-T (Ethernet), full duplex
100BASE-TX (Fast Ethernet) and1000BASE-T(Gigabit Ethernet, or GbE)
networks. The Cat 5e standard provides performance of up to
100MHzand can be used up to a maximum length of 100 meters.This
type of cable is used in structure cabling for computer networks
such as Ethernet. It is also used to carry other signal such as
telephone and video.
Cat 6 cableShort for Category 6, Cat-6networkcabling is used as
the cabling infrastructure for 10BASE-T (Ethernet), 100BASE-TX
(Fast Ethernet),1000BASE-T(Gigabit Ethernet, or GbE) and 10GBASE-T
(10-Gigabit Ethernet, or 10 GbE) networks. The Cat 6 standard
provides performance of up to 250MHz(500 MHz for the newer Cat 6a
standard) and can be used up to a maximum length of 100 meters (55
meters for 10GBASE-T networks).The heavier wire in some Cat 6
cables makes them too thick to attach to standard8P8Cconnectors
without a special modular piece, resulting in a technically
out-of-compliance assembly.Because the conductor sizes are
generally the same, Cat 6 jacks may also be used with Cat 5e
cable.
B- LAN Networking Equipment (add lines if necessary)Equipment
NameDescription Usage
LAN ChipProvide wireless local area network connectivity in a
system-on-chip platform. A LAN chip is a device on an Ethernet
network that broadcasts information and provides Ethernet functions
including PHY receivers and media access control (MAC). It can also
encrypt and decrypt packets as they sent or received without
increasing latency for unencrypted packets. LAN chip are available
as wireless chip which has a wireless communication system built in
it. This type of LAN chip can transfer high-definition files and it
can also provide broadband communication over several miles, unlike
WIFI. LAN chips, such as WLAN chips enable WiFI connectivity to
mobile devices, such as cell phone.
Network RepeaterA network repeater is a device used to expand
the boundaries of a wired or wireless local area network (LAN). In
the past, wired repeaters were used to join segments of Ethernet
cable. They would amplify the data signals before sending them on
to the uplinked segment, thereby countering signal decay that
occurs over extended lengths of wire. But Modern Ethernet networks
use more sophisticated switching devices, leaving the wireless
flavour of the network repeater a more popular device for use with
wireless LANs at work and home. Repeaters used to extend the range
of wireless networks and fibre optic communication systems. How
network repeaters works? Network repeaters use various retiming and
amplification techniques for signal regeneration. In Ethernet
network, they also use partitioning to prevent the propagation of
faults from one network segments to the entire network.
Network TransceiversNetwork transceivers, short for
transmitter-receiver, are devices that both transmit and receive
analog or digital signals. Network transceivers are available in
three main configurations which is chip, board or module style. For
many LANs, the transceiver is built directly into the network
interface card (NIC). Some types of networks, however, require an
external transceiver. Network transceivers apply signals onto a
network wire and detect signals passing through the same wire. In
LAN, they may be used with networking repeaters, devices that
regenerate or retime signals to ensure that these signals are
transmitted through all network segments.
HubsA hub is a small rectangular box, often made of plastic that
receives its power from an ordinary wall outlet.A hub joins
multiple computers or other network devices together to form a
single network segment.
C- WAN Networking Equipments (add lines if necessary)Equipments
NameDescription Usage
SwitchesA network switch (sometimes known as a switching hub) is
a computer networking device that is used to connect devices
together on a computer network. A switch is considered more
advanced than a hub because a switch will only send a message to
the device that needs or requests it, rather than broadcasting the
same message out of each of its portsnetwork device that selects a
path or circuit for sending a unit of data to its next destination.
Operates at layer 2, and uses MAC addresses to send data to correct
destination.
RoutersA router is a device that forwards data packets between
computer networks, creating an overlay internetwork. A router is
connected to two or more data lines from different networks. When a
data packet comes in one of the lines, the router reads the address
information in the packet to determine its ultimate
destination.
connects a local area network (LAN) to a wide area network (WAN)
handles the task of routing messages between the two networks.
Operates at layer 3, and makes decisions using IP addresses.
Optical fiber cableAn optical fiber cable is a cable containing
one or more optical fibers. The optical fiber elements are
typically individually coated with plastic layers and contained in
a protective tube suitable for the environment where the cable will
be deployed. Different types of cable are used for different
applications, for example long distance telecommunication, or
providing a high-speed data connection between different parts of a
building.Using optical fiber a company can transmit huge video
files across the country as fast as it can send them to the office
down the hall.
Virtual Private NetworkA virtual private Network (VPN) extends a
private network across a public network, such as the Internet. It
enables a computer to send and receive data across shared or public
networks as if it were directly connected to the private network,
while benefiting from the functionality, security and management
policies of the private network.[1] This is done by establishing a
virtual point-to-point connection through the use of dedicated
connections, encryption, or a combination of the two.It sets its
router to transfer data from one particular LAN toanother
particular LAN, much like a point-to-point connection
usingTelephone lines. Its called virtual because it really doesnt
create a private network but instead uses parts of the (public)
Internet.
Leased LineA leased line is a service contract between a
provider and a customer, whereby the provider agrees to deliver a
symmetric telecommunications line connecting two or more locations
in exchange for a monthly rent (hence the term lease). It is
sometimes known as a "private circuit" or "data line" in the
UKinvolve a direct point-to-point connection between two sites.
Point-to-point WAN service may involve either analog dial-up lines
or dedicated leased digital private lines.
ModemsShort for modulator/demodulator, a modem enables a
computer to communicate with other computers over telephone lines.
Operates at layer 1, where signals are converted from digital to
analogue and vice versa for transmission and receiving.
connect the computer to the telephone line. Analog lines may be
part of a public-switched telephone network and are suitable for
batch data transmissions.
File Servera file server is a computer attached to a network
that has the primary purpose of providing a location for shared
disk access, that can be accessed by the workstations that are
attached to the same computer networkshared storage of computer
files (such as documents, sound files, photographs, movies, images,
databases)
WorkstationA workstation is a computer designed for technical or
scientific applications. Intended primarily to be used by one
person at a time, they are commonly connected to a local area
network and run multi-user operating systems. The term workstation
has also been used loosely to refer to everything from a mainframe
computer terminal to a PC connected to a network,perform
administrative tasks on a local or remote workstation. Only a user
or application with admin group membership, on a local or remote
server, can perform administrative tasks on a workstation to
control its operation, user access, and resource sharing. For more
information about calling functions that require administrator
privilege
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