IT 105 - Quiz 3

Review Notes for IT 105 Quiz 3

(CH 13.1 | Keyword) - Open Systems Interconnection Reference Model (OSI)

A theoretical model, developed over many years as a standard by the International Standards Organzation (ISO)

(CH 13.1 | Keyword) - TCP/IP

An older and more practical model independently developed to meet the needs of the original Internet design, and regularly modified and updated to meet current needs

(CH 13.1 | Keyword) - Protocol Stack

Each layer of the stack at the sending node contributes information that will be used by the corresponding peer layer at the receiving node

(CH 13.2 | Keyword) - Application Layer

The top level of the suite, sometimes referred to as layer 5

(CH 13.3 | Keyword) - Ethernet Packet

(CH 13.3 | Keyword) - Frame

The bit of an Ethernet packet

(CH 13.3 | Keyword) - Physical Layer

The layer at which the communication actually takes place

(CH 13.3 | Keyword) - Data Link Layer

Responsible for the reliable transmission and delivery of packets across the communication link between two adjacent nodes

(CH 13.3 | Keyword) - Medium-Access Control (MAC)

Defines procedures for accessing the channel and detecting errors

(CH 13.3 | Keyword) - Logical Link Control (LLC)

Offers traffic flow control, error correction, and the management of IP packet/frame conversions, retransmission, and packet reconstruction, when necessary

(CH 13.3 | Keyword) - Collision

Multiple nodes accessing a network simultaneuosly in such a way that their messages become mixed together and garbled

(CH 13.3 | Keyword) - Carrier Sense Multiple Access with Collision Detection (CSMA/CD)

A network protocol used in Ethernet networks to manage access to a shared communication medium

(CH 13.3 | Keyword) - Mac Address

The address for each node on an Ethernet network

(CH 13.3 | Keyword) - Network Propogration Delay

The amount of time it takes for a packet to get from one end of the network to the other

(CH 13.3 | Keyword) - Ad Hoc Mode (Wi-Fi)

Assumes direct connections between Wi-Fi nodes, and is based on a partial mesh network topology. Rarely used since it depends on a network of available cooperative stations

(CH 13.3 | Keyword) - Infrastructure Mode (Wi-Fi)

More common; is based on a shared access point. A variation of CSMA/DC is used for this mode of Wi-Fi

(CH 13.3 | Keyword) - Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)

A network protocol, primarily used in wireless networks like Wi-Fi, that aims to prevent data collisions during transmission

(CH 13.4 | Keyword) - Network Layer

Responsible for the addressing and routing of packets from the source end node through intermediate nodes, step-by-step, to their proper final destination

(CH 13.4 | Keyword) - Internetworking Layer (IP Layer)

Another name for the TCP/IP network layer; IP is the single standard protocol for this layer, although there are two versions (IPv4 and IPv6) in current use

(CH 13.4 | Keyword) - Physical Address

Used by the data link layer for error reporting, making infromation requests, and other auxilary tasks

(CH 13.4 | Keyword) - IP Datagram

The fundamental unit of data transmission in the Internet Protocol (IP); this is what packets are referred to as at the IP level

(CH 13.4 | Keyword) - Layer 3 Switches

Routers and gateways are referred to as this; indicates which layer the routing takes place in

(CH 13.4 | Keyword) - Fragments

IP datagrams that are divided into smaller packets and delivered as fraes to the data link layer; IPv4 has this capability, but it isn’t necessary since the linkages of modern systems are based on Ethernet

(CH 13.4 | Keyword) - Best-Effort Delivery Service

A term to describe IP, meaning it does not guarantee delivery nor check for errors

(CH 13.4 | Keyword) - Address Resolution Protocol (ARP)

IP address-to-physical address translation is performed in conjunction with this support protocol. ARP is implemented at the network layer

(CH 13.4 | Keyword) - Internet Control Message Protocol (ICMP)

An auxiliary protocol that creates error messages that occur when there is a failure in the procedures

(CH 13.5 | Keyword) - Transport Layer

Takes messages from network applications and provides services that support reliable end-to-end communications

(CH 13.5 | Keyword) - Packetization

The breaking up of the message into packets of reasonable size

(CH 13.5 | Keyword) - Port Addresses

Used by the transport protocol to identify the appplication that created the message and the application that is meant to receive the message; also know as port numbers. These are 16 bits in length

(CH 13.5 | Keyword) - Well-Known Ports

The first 1,024 port numbers

(CH 13.5 | Keyword) - Socket

An interface provided by the operating system that makes it easier to add a request ot the communication services provided by the TCP/IP suite

(CH 13.5 | Keyword) - Connection-Oriented Service

A technique that is typically used to transport and send data at session layer; the TCP is considered this

(CH 13.5 | Keyword) - Reliable Delivery

TCP is known as this type of service, since it establishes a full-duplex connection that allows data packets and acknowledgement packets to flow through the channel simultaneously

(CH 13.5 | Keyword) - Logical Connection

A connection that opens to pass data in the form of a byte stream from an application at the sending node to the corresponding application of the receiving node, without regard for the details of the underlying mechanism. This connection operates independently of the actual physical characteristics of the network

(CH 13.5 | Keyword) - Segments

Another name for TCP packets by some network practitioners. This is because their data content is part of an ordered sequence of bytes that is maintained across an entire packetized message

(CH 13.5 | Keyword) - Handshake

A brief back-and-fourth series of requests and acknowledgements

(CH 13.5 | Keyword) - User Datagram Protocol (UDP), or User Datagrams

Used for some applications instead of TCP; is a connectionless service, meaning no connection between the sender and receiver nodes to set up a connection in advance

(CH 13.5 | Keyword) - Stream Control Transmission Protocol (SCTP)

Offers features similar to TCP, with additional features that improve fault tolerance and enables multiple messages (in the form of byte streams) ot be transported simultaneously through the same connection

(CH 13.6 | Keyword) - IP Address

The standard for locating resources on the Internet. IP address and domain names are registered and allocated by ICANN

(CH 13.6 | Keyword) - IPv4

Has an address that is 32 bits long, which is divided into four octets or bytes; separated by dots for easier reading

(CH 13.6 | Keyword) - IPv6

Has an address that is 128 bits long, permitting 2128 (256 trillion trillion trillion) different IP addresses

(CH 13.6 | Keyword) - Subnets

The remaining bits of an IPv4 address. These addresses are typically divided into three levels, the top level being the network address

(CH 13.6 | Keyword) - Masks

Used to separate the different parts of the address

(CH 13.6 | Keyword) - Network Address Translation (NAT)

Passes messages from the isolated network to the Internet, replacing the private address with the router’s IP address

(CH 13.6 | Keyword) - Static Address

IP address that are more-or-less permanently assigned to a device

(CH 13.6 | Keyword) - Dynamic Address

IP addresses that are assigned on an as-needed basis

(CH 13.6 | Keyword) - Dynamic Host Configuration Protocol (DHCP)

An application layer protocol used to assign and reclaim IP addresses from a pool of addresses when a computer is connected to or removed from a network

(CH 13.6 | Keyword) - Colon-Hexadecimal Notation

A sequence of eight four-digit hexadecimal numbers separated by colons

(CH 13.7 | Keyword) - Domain Name System (DNS)

A support application that translates domain names into IP addresses

(CH 13.7 | Keyword) - DNS Root Server

The root directory, located at the top of the directory system

(CH 13.7 | Keyword) - Top-Level Domains

Root servers that are distributed geographically which reduces the amount of long distance traffic by providing nearby access for as many queries as possible

(CH 13.7 | Keyword) - Country-Code Top-Level Domain Name Servers (ccTLDs)

Servers for every identifiable country in the world plus a number of authorized commerical and noncommercial generic top-level domain name servers (gTLDs)

(CH 13.7 | Keyword) - Generic Top-Level Domain Name Servers (gTLDs)

Includes .com, .edu, .org, .net, and more

(CH 13.7 | Keyword) - Second-Level, or Third Level Domains

Domain names below the top-level. These are registered for a small fee by users with one of a number of registrars. ICANN assumes overall responsibility for the millions of registered names on the Internet

(CH 13.7 | Keyword) - Authoritative Domain Name Server

Each individual domain must register the IP address of the domain name service of its own to identify its host and sub domains, if any

(CH 13.7 | Keyword) - Replication

The periodic updating and sychronization of a server table

(CH 13.7 | Keyword) - Resolution

The translation process that takes place when a user types a URL into their Web browser application

(CH 13.7 | Keyword) - Local DNS Server

A type of DNS server that resolves domain names within a specific local network, such as a home or office network

(CH 13.8 | Keyword) - Quality of Service (QOS)

Focuses on two parameters: (1) Methods to reserve and prioritize channel capacity to favor packets that require special treatment; (2) Service guarantees from contracted carrier services that specify particular levels of throughput, delay, and jitter

(CH 13.8 | Keyword) - Jitter

Defined as the variation in delay from packet to packet

(CH 13.8 | Keyword) - Differentiated Service (DS)

A 6-bit field and network architecture that provides Quality of Service (QoS) by classifying and managing network traffic

(CH 13.9 | Keyword) - Electronic Signatures

Verifying the identity of a source of data being received. Similar to the concept of authentication

(CH 13.9 | Keyword) - Packet Sniffing

Defined as the reading of the data in a packet as it passes through a network

(CH 13.9 | Keyword) - Symmetric Key Cryptography

Requires that the same key be used for both encryption and decryption. This means that both users must have access to the same key, which is often difficult to achieve securely

(CH 13.9 | Keyword) - Public Key-Private Key Cryptography

Two different keys, one publicly available, the other private, are used together in various ways to achieve their goals

(CH 13.10 | Keyword) - Session Layer

Responsible for establishing the session between the applications, controlling the dialogue, and terminating the session

(CH 13.10 | Keyword) - Presentation Layer

Provides common data conversions and transformations that allow systems with different standards to communicate

(CH 13.10 | Keyword) - SONET (Synchronous Optical Network)

A relatively obsolete protocol suite that operates similarly to the OSI reference model, or implements parts of it; a standardized protocol for transmitting digital data over optical fiber at high speeds

(CH 13.10 | Keyword) - SDH (Synchronous Digital Hierarchy)

A relatively obsolete protocol suite that operates similarly to the OSI reference model, or implements parts of it; a standardized technology used for high-speed, synchronous optical communication over fiber-optic networks

(CH 13.10 | Keyword) - Frame Relay

A packet-switching technology used in wide area networks (WANs) to transmit data between local area networks (LANs)

(CH 13.10 | Keyword) - Long-Term Evolution (LTE)

The global mobile communication standard; based primarily on OFDM and QAM techniques

(CH 13.10 | Keyword) - Handoff

The number of simultaneous users and the movement of the users from cell to cell

(CH 13.10 | Keyword) - MPLS (Multi-Protocol Label Switching

Improves the forwarding speed of IP datagrams by creating virtual circuit capabilities over traditional packet switched networks, such as Ethernet

(CH 14.2 | Keyword) - Signals

The means used to communicate data; carried on a communication channel as an electrical voltage, an electromagnetic radio wave, ot a switched or modulated light

(CH 14.2 | Keyword) - Analog Signal

A signal that takes on a continuous range of values

(CH 14.2 | Keyword) - Discrete Signal

A signal that only takes on discrete values

(CH 14.2 | Keyword) - Digital Signal

A binary discrete signal

(CH 14.2 | Keyword) - Waveform

A representation of a signal shown as a function of time

(CH 14.2 | Keyword) - Sine Wave

A basic unit of analog transmission

(CH 14.2 | Keyword) - Amplitude

The size of a wavelength

(CH 14.2 | Keyword) - Frequency

Measures as the number of times the sine wave is repeated per second

(CH 14.2 | Keyword) - Period

The amount of time it takes to trace out one complete cycle of a sine wave

(CH 14.2 | Keyword) - Hertz

The unit used to measure frequency

(CH 14.2 | Keyword) - Wavelength

The physical length of a sine wave that is traveling in space at the speed of light

(CH 14.2 | Keyword) - Radians

The angle subtended at the center of a circle by an arc with a length equal to the radius of the circle

(CH 14.2 | Keyword) - Phase

The difference between the position of a sine wave with respect to a reference sine wave, measured in degrees

(CH 14.2 | Keyword) - Spectrum

The constituent frequencies that make up a signal

(CH 14.2 | Keyword) - Bandwidth

The range of frequencies that are passed by the channel with only a small amount of attentuation

(CH 14.2 | Keyword) - Filtering

An electronic mean to control the bandwidth of a channel; also used to separate the bands in frequency-division multiplexing

(CH 14.2 | Keyword) - Amplitude-Modulated

The modulation of a wave by varying its amplitude, used chiefly as a means of radio broadcasting, in which an audio signal is combined with a carrier wave

(CH 14.2 | Keyword) - Detector

Restores the original waveform that was used to modulate the carrier

(CH 14.2 | Keyword) - Amplitude Shift Keying (ASK)

A digital modulation technique where the amplitude of a carrier signal is varied to represent binary data

(CH 14.2 | Keyword) - Frequency Shift Keying (FSK)

A digital modulation technique where data is transmitted by changing the frequency of a carrier wave

(CH 14.2 | Keyword) - Phase Shift Keying (PSK)

A digital modulation technique where data is encoded by varying the phase of a carrier signal

(CH 14.2 | Keyword) - Frequency-Division Multiplexing

A technique that divides a communication channel's bandwidth into smaller, non-overlapping frequency bands, each carrying a separate signal

(CH 14.2 | Keyword) - Wavelength-Division Multiplexing

A technology that enables multiple optical signals, each with a different wavelength, to be transmitted simultaneously over a single optical fiber; differentiates optical multiplexing from lower frequency radio multiplexing

(CH 14.2 | Keyword) - Attentuation

The reduction of a signal that occurs in a medium as a function of the physical length of the channel

(CH 14.2 | Keyword) - Amplifiers

Can be used to restore the original strength of the signal

(CH 14.2 | Keyword) - Asynchronous Transmission

A method of transmitting data where each character or data unit is sent individually, with its own start and stop bits to indicate its beginning and end, rather than relying on a continuous, synchronized stream

(CH 14.2 | Keyword) - Manchester Encoding

A data encoding technique where both the clock signal and data are combined into a single signal stream for transmission