CIS 317

A desktop computer cannot be connected to a local area network using a wireless connection. T or F?

False

Two local area networks can connect to share peripherals as well as software. T or F?

False

Amplitude

Height of a wave (This often denotes the voltage level of the signal)

The devices found in the data link layer are

Hubs, swithces

The main address of the network layer is the

IPv4 (32 bit) address Assigned to each host to access the internet

Noise spike is also known as:

Impulse noise

Frequency of a Signal

The number of times a signal makes a complete cycle in a second measured in Hz

Payload

The part of a frame that holds the actual data that needs to be transmitted

Encapsulation

The process of adding control information to a packet as it moves through the network layer

What factor limits the transmission range of the Microwave?

The sender and receiver of a microwave signal must be within each other's sight

What is the purpose of twisting wires in twisted-pair cables?

To improve the quality of the signal and minimize cross talk

The TCP/IP ____ commonly uses the Transmission Control Protocol (TCP) to maintain an error-free end-to-end connection.

Transport Layer

Many years ago, most home users connected their computers to the Internet via a dial-up telephone line and a modem, but now the more common connection is using DSL. T or F?

True

The data link layer of the OSI model can incorporate some form of error detection software. T or F?

True

Thick coaxial cable has better noise immunity than thin cable. T or F?

True

White Noise can not be completely eliminated. T or F?

True

Examples of WIRELESS computer networks that use radio waves include:

broadcast radio, microwaves, or satellite transmissions

Infrared Transmission

is a special form of radio transmission that is used in remote controls with a focused ray of light in the (1012-1014MHz) frequency range.

FEC (Forward Error Correction)

is an effective digital signal processing method that improves the bit error rate of communication links by adding redundant information (parity bits) to the data at the transmitter

Data is...

is information that has been translated into a form that is more conducive to storage, transmission, and calculation.

Noise

is unwanted electrical or electromagnetic energy that degrades the quality of signals and data.

The main device of the physical layer is a

repeater

In order to connect a LAN to the internet, it needs to be connected to a ______

router

LEO (Low Earth Orbit)

satellite located apx. 100-1,000 miles outside of earth. Used for data communication like cell services, wireless email, videoconferencing, etc.

The data unit of the physical layer is called the

signal

The period of a signal can be calculated by...

taking the reciprocal of the frequency (1/frequency).​

The main address of the data link layer is

the MAC address (48bit) assigned to the hardware by the manufacturer

To transmit digital data using digital signals, the 1s and 0s of the digital data must be converted using _____ algorithms

Encoding

The two main protocols of the data link layer are

Ethernet & Wi-Fi

Digital to Analog

Examples include DSL modems and Dial up and Cable modems

_____ is used to transfer files from one computer system to another

FTP or File Transfer Protocol

The data unit of the network layer is a

Packet

In wireless media, ______ carry data through the air such as radio waves

Electromagnetic waves

Router

A device that converts the LAN data to WAN data

Repeater

A device that receives an attenuated signal and amplifies it

Metropolitan Area Network (MAN)

A high-speed network that interconnects multiple sites within a close geographic region, such as a large urban area.

FDMA (Frequency Division Multiple Access)

-Bandwidth is divided into N portions among N users -Works for a small number of network users -static allocation such as FM radio stations

TDMA (Time Division Multiple Access)

-Time is divided into N portions among N users -Efficient when there is a constant number of users with a constant data rate

Star Topology

1. Each device as a dedicated point-to-point link 2. the entire system is dependent on the HUB 3. if one link fails, the others are fine 4. twisted pair cable is typically used

Main Functions of a LAN

1. File Sharing 2. Print Serving 3. Database and Application Serving 4. Access to the Internet

List the 5 duties of the network layer

1. Internetworking 2. Packetizing 3. Addressing 4. Routing 5. Fragmentation

Cons of terrestrial microwave transmission include:

1. Land-Based, Line-of -sight transmission 2. Can only have a distance of apx. 15-30 miles between each transmitter 3. Signals do not pass through solid objects 4. Expensive

Virtual Circuit (Physical Connection)

1. Network should provide a reliable, connection oriented service 2. quality of service is the dominant factor, and without many connections in the network there is poor quality of service

Three examples of Error detection

1. Parity 2. Checksum 4. CRC (Cyclic Redundancy Check)

The two types of network links are:

1. Point-to-point (Dedicated) such as old telephone systems 2. Multipoint (Shared) such as LANs

Terrestrial Microwave Transmission is most commonly used for:

1. Telephone Communication 2. Business interconnections (Connecting corporate buildings every 15-30 miles)

Two Main Functions of the Data Link layer

1. The delivery of frames across links 2. Error & Flow control

Mesh Topology

1. all devices are physically connected 2. if one fails, it will not ruin the entire network 3. expensive, lots of cabling

Ring Topology

1. each device has a dedicated point-to-point link 2. each device in the link works as a repeater 3. easy to install and reconfigure 4. a break in the ring can disable the entire network (old school IBM networks)

Two advantages of fiber optic cables are:

1. improve security because it is impossible to wire tap 2. immune to noise and electromagnetic interference

Bus Topology

1. one long cable acts as a backbone to link all devices in the network 2. easy to install 3. difficult fault isolation 4. one break stops all devices in the connection

Datagram (Internet Connection)

1. routers job is moving packets around & nothing else 2. network is inherently unreliable 3. Host should do flow control and error control themselves and should not rely on the network to do so

Protocol

A set of rules used by communication devices to format signals that are transmitted

A Switch is...

A smart signal processing device that has an internal processor, Random Access Memory (RAM), and switching table. This device can determine the MAC address of connecting devices so that it can more "directly" sent data.

Domain Name System (DNS)

A supporting application that works in the background to connect IP addresses to things like web DNS servers and web services

Wimax

A system bypasses the telephone company's local loop by transmitting voice, data, and video over very high radio frequency

the reference model/s to standardize the design of communication systems and the interoperability between their components

A, B

Three important data codes are EBCDIC, ____, and Unicode

ASCII

In wired media, ______ carries data through cables such as telephone lines

Electrical Signal

AM and FM radio channels are examples of (which kind of data signal combo)?

Analog data to analog signal conversion

1. ____ is a continuous waveform, such as a human voice 2. Between two given points, there are an unlimited number of values

Analog signal

A type of CAT wire that was created to carry analog voice or data at low speeds less than 9600 bps

CAT1

A cable designed to transmit 100 Mbps of data for distances up to 100 meters with 100MHZ frequency. It has more twists per inch than other CAT cables and, as such introduces less noise. It can provide full-duplex through 4 pairs of wires, 2 pairs for sending and 2 pairs for receiving signals. It is widely used in LANs.

CAT5

Wires are twisted in ______, because having perpendicular wires is impossible.

CAT5

HI frequency waves such as UV waves and Microwaves...

Can't pass through walls and move freely. These are typically used for medical purposes

Because of its good shielding properties, ____ is good at carrying analog signals with a wide range of frequencies.

Coaxial cable

1. _____ is a form of information that is produced and consumed by a computer 2. To transmit _____ over communication lines, it has to be converted into a signal

Data

The ____ layer of the OSI model is responsible for taking data from the network layer and transforming it into a frame.

Data Link

transmitting digital data of computers using digital lines such as CAT5 cables in LANs is an example of

Digital to Digital signal

To transmit data, a light source, such as a photo diode, is placed at the transmitting end and quickly switched on and off to produce light pulses

Fiber Optic Cable

The Data unit of the data link layer is a:

Frame

FM stations use...

Frequency modulation

An example of MEO (Middle-Earth-Orbit) includes ____ systems of 24 satellites that were launched by the U.S. Department of Defense

GPS

_____ allows Web browsers and servers to send and receive web pages.

HTTP or Hypertext Transfer Protocol

The main protocol of the network layer is the

Internet protocol

Digital to Digital

Known as ENCODING; Examples include LANs, small computer networks, and ethernet

Analog to Analog

Known as MODULATION Examples include AM & FM radio

A ____ is an interconnection of computers and computing equipment using either wires or radio waves over small geographic areas.

LAN or Local Area Network

The light source for a fiber optic cable can be either a simple and inexpensive _____, or a more complex _____.

LED, Laser

______ is the type of conducted medium that can be employed in Wide Area Networks.

Laser fiber-optic

In the Ethernet header, the destination address is a ____.

MAC address

Analog to Digital

Manchester Modulator; Examples include Music Production systems and some telephone systems

The ____ layer is the OSI layer that handles routing.

Network

A device that connects various segments of a network by amplifying the signal

Repeater

Synchronization Issues NRZL & NRZI encoding...

Results when a chain of zeros produces no change in signal and is not picked up well by a receiver

A high-speed ______ is required to connect two wide area networks

Router

The devices found in the network later is/are

Routers

Bandwidth

The absolute value of the difference between the lowest and highest frequencies of a signa

Satellite microwave transmission systems are similar to terrestrial microwave systems except that the signal travels from a ground station on Earth to a satellite and back to another ground station on Earth. T or F?

True

Manchester Encoding has a baud rate that is ___ the bps

Twice

Highly elliptical orbit (HEO) satellites are...

Used in meterology and are about 3,000-22,200 miles outside earth.

Modulation

When analog data is going to be transmitted using analog signals by varying amplitude, frequency or phase of the carrier signal

Attenuation

When traveling through any type of medium, a signal always experiences some loss of its power due to friction. This loss of power, or loss of signal strength, is called ____.

Sliding Window

a flow-control scheme that allows a station to transmit a number of data packets at one time before receiving some form of acknowledgment.

frame

a group of bits in the data link layer

Jitter is....

a kind of noise that can result from small timing irregularities during the transmission of digital signals and can become magnified as the signals are passed from one device to another

A Hub is...

a non intelligent signal processing devices that broadcasts network signals

Flow Control Process

a process that keeps a transmitter from sending too much data to a receiver

The MAC address is...

a unique address assigned to hardware by manufactures based on their Network Interface Card (NIC)

AM Radio stations use...

amplitude modulation

GEO satellites

are located 22,300 miles outside of earth and are used for gov't/spying/ purposes unknown to the general public.

LO frequency waves such as Radio, Telephone, Cellular, and Satellite Microwaves...

can move more freely and are more accessible than HI freq. waves

______ cables are used for long-distance telephone transmission, and cable TV networt, are single copper wire wrapped in foam insulation, surrounded by a braided metal shield, and then covered in a plastic jacket, and most used in BUS topology of LANs

coaxial

Flow Control

controls the data between 2 servers and must receive acknowledgement before sending out data

Packetizing

dividing a larger message into packets for data transfer

Fragmentation

due to the capacity of networks, packets are fragmented into smaller ones to be sent and received at different speeds

Crosstalk

noise that happens with twisted pair wires, such as an Ethernet cable, can be electrical.

Switches

points for the wires that interconnect the workstations of a LAN

Modulaion

the process of sending data over a signal by varying either its amplitude, frequency, or phase

Echo is

the reflective feedback of the transmitted signal as the signal moves through a medium

Hand Off transfer

the transfer of mobile users from a cell tower to adjacent towers

In twisted-pair cable, the ideal is:

to have wires perpendicular to each other to minimize cross talk

In Manchester Encoding...

to transmit a 1, the signal changes from low to high in the middle of the interval, and to transmit a 0, the signal changes from high to low in the middle of the interval

The difference between NRZL and NRZI is that...

with NRZL, the receiver must check the voltage level for each BIT to determine weather the bit is a 0 or 1 With NRZI, the receiver must check to see if there's a change at beginning of the bit to determine if it is 0 or 1