worksheet 4 - assignment 1 revision

8/3/2019 Worksheet 4 - Assignment 1 Revision

1/12

Networking Technology Worksheet 4 1.

Q1. Name and describe the most popular media that exist for data transmission.

Q2. What is crosstalk? How is it caused?

Q3. What are EMI and RFI? How can these affect signal transmission?

Q4. Why is proper cable termination essential? What can improper termination cause?

Worksheet 4: Assignment 1 Revision

Name:

Surname:

Group:

NETWORKING TECHNOLOGYSecond Year Higher National Diploma

Copper, Fibre, Wireless (Air)

Examples of Which: Copper: Twisted Pair,Coaxial

Fibre: Multimode, Singlemode

Crosstalk is caused by the electromagnetic signals interferingwith each other through cables passing through with each other

in parallel.

Twisted Pair cabling Prevents this, because the twists with the

wires cancel crosstalk out. the tighter the twists, the less

crosstalk affects the signal.

EMI - Electromagnetic Interference and Radio Frequency Interference

cause performance degradation in media that utilise Electromagneticwaves as their means of transmission.

Proper Cable Termination is extremely important, because if termination

is not done correctly, Insertion loss can be caused, and performance

degradation and data loss can be increased exponentially.

Improper termination causes increased crosstalk.


2/12


Q5. How are signals transmitted through fiber optic media? Explain the two modes of transmission

that are most popularly used?

Q6. Mention and briefly explain the components making up a fiber optic cable.

Q7. What does VCSEL mean? What is it used for?

Q8. Mention and briefly explain the components making up a coaxial cable.

Optical Fibre transmits data through light. the two methods are:

Single Mode Transmission, which is the longest range transmission method

with a range of over 5 km, Single mode transmits it's data through

a single ray of light.

Multi Mode Transmission utilises a thicker cable, and transmits datathrough multiple rays and the use of total internal reflection.

with a higher bandwidth, and the feature of multiplexing, Multimode

Cabling has a shorter range, limited to about 500m.

Fibre Optic Cabling is protected by the following layers of protection:

Fire Proof Sheath

Kevlar Sheilding

Buffer

Cladding

and then the fiber core.

VCSEL - Vertical Cavity Surface Emitting Lasers are used in multimode

fiber cabling to transmit data via Laser instead of LEDs.

a Coaxial Cable comprises of the following components.

The Copper Core

Cladding (Copper Mesh)

Buffer

and Plastic Shield.


3/12


Q9. What does FLUKE test a copper cable for?

Q10. List the three main types of twisted-pair configurations and briefly explain their use.

Q11. Identify the transmission speed, transmission mode, medium, and cable length described by the

following standard media notations:

10Base5:

10Base2:

10BaseT:

100BaseTX:

1000BaseSX:

1000BaseLX:

a FLuke Test Tests copper cables for:

Termination, Speed, Continuation, Wire Mapping, Meeting of Standards

and Basic Troubleshooting

Straight Through = Used with Different Devices which transmit and

recieve data between each other.

Crossover = Used to transmit and recieve data between like devices.

Rollover = used to connect with Cisco Routers to access their

operating system.

Thicknet - 10mbits - 500 meter Range

Thinnet - 10mbits - 200 meter Range

Twisted Pair - 10 mbits - 100 meter Range

Fast Twisted Pair - 100mbits, 100 meters

1 Gigabit - MultiMode Fiber - 220 Meters 550 Meters Range.

1 Gigabit - Multimode/Single Mode Fiber - 5 Km Range


4/12


Q12. Name three (3) common IEEE 802.N standards.

Q13. List the name of the terminators used with copper media and fiber optic media over networks.

Q14. What is the difference between broadbandand baseband?

Q15. What is the difference between bandwidth and throughput?

Q16. Mention and explain different Media Access Control mechanisms.

802.11 - Wireless

802.5 - Token Ring

802.3 - Ethernet

RJ-45

RJ-11

BNC

SC, LC, ST, TOSLINK

baseband - Uses a Single Frequency to transmit data, is usually the

highest.

broadband - uses all of the available frequencies on any given media.

Bandwidth is a literal measure of the capacity of a waveband. The wider the

wave is, the more data it can handle at any one time. Throughput is the

speed at which data is transmitted.

CSMA/CD - Collision Detection - Manages Collision Detection by clearing the

media for a random amount of time, then allows data to restart transmission

CSMA/CA - Collision Avoidance, prevents data collisions by only granting

permission to data transmission whenever the medium is clear of data.Token Ring - Allows data transmission to the host that holds the token that

is passed from one computer to another.


5/12


Q17. In what ways does a NOS provide ways to install, configure and maintain network adapters?

Q18. Identify and briefly describe 4 common NIC features which are used as a basis for network card

selection.

Feature 1:

Feature 2:

Feature 3:

Feature 4:

Q19. What is the use of the following NIC components or features?

DMA Bus Access:

CPU:

A NOS utilises protocols to control transmission, and recieval of data.

NOSs also allow administrators to configure Network Cards.

Connection Speed: The Maximum Speed at which the NIC Card can

transmit data.

Cost

Combo - NIC Cards that support more than one different

Medium.

Wake On LAN, Buffer Size etc...

Allows access to the RAM without CPU Intervention

The CPU on a NIC Card takes on the load of managing data recieval and

transmission from the Main CPU.


6/12


Memory:

LEDs:

Transceiver:

Q20. Write all you know about CAT5, CAT6 and CAT7 cables?

Q21. Identify and explain the elements that you would consider when planning the network

infrastructure for a particular site?

The Buffer on a NIC Card stores the data that is being transmitted,

and reduces the RAM load.

The LEDs on a NIC Card indicate the Card's activity. Green indicatespower, while Orange indicates activity.

a Transciever Recieves and transmits data.

CAT 5 - Standard Unsheilded UTP Cabling, The original Standard Supported

up to 10mbits, but CAT 5e supports up to 100mbits.

CAT 6 - Features tighter twists, a plastic border between the pairs, and

can support up to 1000bits transmission speed.

CAT 7 is Fully shielded STP Cabling. It fully supports Gigabit Ethernet,

and consists, of tighter Twists than CAT6, individually foil wrapped pairs

and an earth cable In order to ensure that the minimum amount of

Electromagnetic interference gets into the cable. (It gets dissipated when

contact with Metal is achieved.)

Floor Plan, Required speeds, Resources required for Client's goals

Budget, Number of Hosts, Departments if Applicable, Hardware

requirements, Centralised or Client Server, Wire Distance etc...


7/12


Q22. What do the terms OFDM and DSSS stand for? Which IEEE 802 Protocols use these methods

of wireless transmission?

Q23. What is the difference between infrastructure and ad-hoc wireless connectivity?

Q24. In which type of wireless association method is probing used? Explain how it works.

Q25. Which type of wireless association method makes use of beaconing? Explain what the process

involves.

Q26. Identify the two main types of wireless antennae that are commonly used, explaining how they

propagate the signal.

OFDM - Orthogonal Frequency division Multiplexing used by 802.11n,b While

DSSS - Direct Sequence Spread Spectrum used by 802.11g,n,a

Infrastructure mode is a wireless extension to a full wired network.

ad-hoc Mode refers to a wireless connection that is established

temporarily, between two different hosts.

Active Scanning is When a Query for Wireless networks is initiated, and

when a Wireless Access point recieves the Probe Frame, it allows the host

to connect to the Wireless Access point.

This is the opposite of Probing. - A Host must have the Access Point's SSID

to connect to the Access Point. this is a more secure method of connecting

to a Wireless Network, as certain details are required to even find the

Access Point.

This is called Beaconing or Passive Scanning.

Omnidirectional - Transmits it's signal in all angles. used in mobile

platforms to connect to wireless access points.

Unidirectional - Used on fixed apparatus to transmit signals. usually

transmits signals in the physical direction of the antenna.


8/12


Q27. What are the physical infrastructural requirements of HomePlug and HomePNA?

Q28. What is the function of a HomePNA Adapter? Which physical properties does it usually have?

Q29. What is the function of a HomePLUG Adapter? Which physical properties does it usually have?

Q30. Write down the services offered by each layer of the OSI Model.

Layer 1:

Layer 2:

Layer 3:

Layer 4:

Home PNA requires a minimum of 2 Home PNA Connectors plugged into an RJ-ll

Socket. HomePlug Requires a minimum of 2 Homeplug connectors plugged into

the Electrical system of a home.

it is usually an adapter which converts the RJ-11 Socket into an RJ-45Connector. it allows the use of Existing Telephony infrastructures to

transmit and recieve data that can only otherwise be used when connecting

to a standard RJ45 Network.

it is usually an adapter which converts an Electrical Socket into an RJ-45

Connector. it allows the use of Existing Electrical infrastructures to

transmit and recieve data that can only otherwise be used when connecting

to a standard RJ45 Network.

Physical Layer - Transmits and recieves data over a physical Medium.

The Data link Layer adds Physical Addressing, and uses The Ethernet

protocol to apply these properties. the sublayers, MAC and LLC define

the media access control method which is usually CSMA/CD or CSMA/CA

and LLC also caters the Frame for the Selected transmission protocol

in the transport layer. Frames

The Network Layer performs Routing Services, and adds IP Addressing to

the Data's header. (source and destination addresses) Packets

Transport Layer Decides what method of connections are to be made for

instance TCP or UDP, and also adds Source and Destination Port Numbers

to the header. it also performs window sizing and sequencing.


9/12


Layer 5:

Layer 6:

Layer 7:

Q31. What do the acronyms PCI, PDU and SDU mean? What do they refer to?

PCI:

PDU:

SDU:

Q32. Explain the prerequisites for the WOL function to properly operate.

Session Layer: The Session Layer Establishes, and Maintains

connectivity between the Source host and the Destination Host.

The Presentation layer Performs Encryption, Encoding and Compression

of the data.

The Application Layer consists of most of the protocols that the user

of the host interacts with. it is the highest level of interaction,

and is the only interaction that the user has with the data to be

sent.

Protocol Control Information - The Header that is to be added to the

Data.

Protocol Data Unit - Is the complete Data packet.

The Service Data Unit is the data that is to have a header attached to

it. It generally descends from higher layers.

For the Wake On Lan to work correctly, the BIOS and NIC Card must support

it. it must maintain power to the motherboard and NIC Card in order to be

able to recieve packets while turned off.


10/12


Q33. What is a Magic Packet? What is it used for?

Q34. List and explain the stages of encapsulation. How does each stage relate to the OSI Model

PDUs?

Q35. List the three main type of switches that exist and highlight their particular functions.

Q36. What does a router require in order to carry out its routing function?

a Magic Packet is used to transmit a command to turn on a pc through WOL.

First a Broadcast packet is sent, FF FF FF FF FF FF

Then the Mac Address of the computer in question is sent 16 times.

Refer to Diagram in handwritten Diagram.

NOT IN SYLLABUS

A Router Requires a Routing table to carry out it's routing functions.


11/12


Q37. What is the difference between Routed, Non-routed and Routing Protocols? Provide examples.

Q38. What does a layer 2 Switch require in order to carry out its packet-switching function?

Q39. Why is TCP considered as a connection-oriented protocol unlike UDP? Explain in detail.

Q40. Describe the process of establishing a connection using TCP.

Q41. What is the difference between the Session Layer and the Transport Layer.

Routing Protocols - Are used for communication between Routers

Routed Protocols - Routed Protocols are used for Data Transfer between

networks. RIP, OSPF, IGRP

Non-Routable Protocols are used in only one network, and cannot be used to

communicate outside a set network or segment.

A Switch requires a Mac Address Table. It is populated in this manner:

Whenever a device is connected to the Switch, the Table becomes updated,

because the switch would broadcast a request for Mac Address information.

TCP is considered as a connection oriented protocol because it ensures

that connectivity is established through a three way handshake.

Information is gathered about the data's destination by performing

a Three way handshake. This discovers the Destination's limitations

Accepted Window Sizes, etc....

SYN -->

The Transport Layer is responsible for handling Data transmission according

to the protocols defined in Earlier Layers. for instance, TCP or UDP and

also assigns Source, and Destination Port Numbers.

While the Session Layer manages the actual connection between The

Applications that are sending and recieving data.


12/12


Q42. Why is the Presentation Layer very important especially when considering an internetwork

infrastructure?

Q43. How does an Application Software differ from the OSI Application Layer?

Q44. Identify and briefly describe six main components of the TCP Segment.

Source Port Destination Port

Windowing

Sequence Number

Acknowledgement Number

The Presentation performs data encryption, compression and encoding.

this allows the data to be sent securely, so that it cannot be compromised

during data transmission.

Data cd

The Application Layer simply consists of the Protocols required to begin

the transmission process, i.e., http, ftp, etc...

while application software is the application which utilises the OSI model

to Start Data Transmission.

worksheet 4 - assignment 1 revision

Documents