Computer Networks and Internet Protocols Flashcards

Flashcards covering key vocabulary terms related to computer networks and internet protocols.

Network Architecture

A way to visualize how two remote computers talk to each other.

Physical Layer Requirement

Convert digital data to analog signal and vice versa

Data Link Layer Requirement

Ensure proper scheduling in media access

Network Layer Requirement

Find out a suitable path to forward data

Transport Layer Requirement

End to end traffic control in the network

Application Layer Protocols

HTTP, FTP, SMTP

Transport Layer Protocols

TCP, UDP, RTP

Network Layer Protocols

IPv4, IPv6, MPLS

Data Link Layer Protocols

Ethernet, WiFi, Bluetooth, UMTS, LTE

Telegraph by Cooke and Wheatstone (1836)

Revolutionized human (tele)communications. Morse Code a series of dots and dashes used to communicate between humans. This is similar to how computers communicate via (binary 0/1)

Transatlantic cable (1858-1866)

Allowed direct instantaneous communication across the Atlantic. Today, cables connect all continents and are still a main hub of telecommunications.

Telephone by Alexander Graham Bell (1876)

Telephones exchanges provide the backbone of Internet connections today. Modems provide Digital to Audio conversions to allow computers to connect over the telephone network.

ARPA (1957)

The US forms the Advanced Research Projects Agency (ARPA) within the Department of Defense (DoD) to build US skills in computer technology. U.S.S.R. launches Sputnik.

ARPANET Foundations (1962)

ARPA's contracts from the private sector to universities and laid the foundations for what would become the ARPANET.

Packet-switching (PS) networks developed (1962-1968)

The Internet relies on packets to transfer data. Data is split into tiny packets that may take different routes to a destination.

ARPANET (1969)

Commissioned by DoD for research into networking. Four (4) nodes: (i) Univ of California, Los Angeles (UCLA); (ii) Stanford Research Institute (SRI); (iii) Univ of California, Santa Barbara (UCSB); (iv) Univ of Utah

Ray Tomlinson (1971)

Invents Email program to send messages across a distributed network. 15 nodes (23 hosts) on ARPANET

Global Networking (1973)

First international connections to the ARPANET: University College of London (England) and Royal Radar Establishment (Norway)

Packets become mode of transfer (1974)

Transmission Control Program (TCP) specified. Packet network Intercommunication -- the basis of Internet Communication. Telenet, a commercial version of ARPANET, opened -- the first public packet data service.

USENET (1979)

Established using UUCP - A collection of discussions groups, news groups.

TCP/IP (1982)

Establishes the Transmission Control Protocol (TCP) and Internet Protocol (IP), as the protocol suite, commonly known as TCP/IP, for ARPANET. TCP/IP defines future network communication.

Domain Name Server (DNS) (1984)

Domain Name Server (DNS) introduced. NSF establishes 5 super-computing centers to provide high-computing power for all -- This allows an explosion of connections, especially from universities.

Commercialization of Internet (1987)

UUNET is founded with Usenix funds to provide commercial UUCP and Usenet access.

World Wide Web (1989)

WWW concept by Tim Berners-Lee

First search engine (1990)

First search-engine (Archie) ARPANET ceases to exist. First browser/editor program.

User Friendly Interface to Internet (1991)

Gopher released by Paul Lindner and Mark P. McCahill from the U of Minnesota. Text based, menu-driven interface to access internet resources.

Surfing the Internet (1992)

The term Surfing the Internet is coined by Jean Armour Polly.

The WWW Revolution truly begins (1993)

The Mosaic Web browser is released on the Net

Important Facts of 1994

Hotmail starts web based email and World Wide Web Consortium (W3C) was founded

Protocol

Defined as controlled sequence of messages exchanged between two or more systems to accomplish a given task.

Physical Layer Function

Transmission of binary data of a medium.

Data Link Layer Function

Transfer of units of information, framing, and error checking.

Network Layer Function

Delivery of packets of information, which includes routing.

Transport Layer Function

Provision for end-to-end reliable and unreliable delivery.

Session Layer Function

Establishment and maintenance of sessions.

Presentation Layer Function

Data formatting and encryption.

Application Layer Function

Network applications such as file transfer and terminal emulation.

Transmission Control Protocol/Internet Protocol (TCP/IP)

Represents a set of public standards that specify how packets of information are exchanged between computers over one or more networks.

Clients

Workstations

Servers

Usually have more computing resources

Network Devices

Repeaters, Hubs, Transceivers, NICs, Bridges, Switches, Routers

Wide Area Network (WAN)

A data communications network covering a large geographic area.

MAC

Stands for Media Access Control

NICs

Provide hosts with access to media by using a MAC address and operate at Layer 2.

Repeaters

Amplify and retime signals and increase the distance 100 meters or approx. 300 feet

Hubs

Share bandwidth between all attached devices, are layer 1 devices and cannot filter traffic.

Bridges

Used to filter frames based on MAC addresses.

Routers

Filter traffic based on IP addresses and tells the router which LAN segment the ping belongs to.

Access Layer

For end user connectivity

Distribution Layer

For policy based routing and access control

Core Layer

For switching packets as fast as possible across the internetwork.

Broadcast Domain

Set of all devices on a network segment that hear all the broadcasts sent on that segment

Collision Domain

Ethernet term used to describe a network scenario in which one particular device sends a packet on a network segment, forcing other devices on the same segment to pay attention to it.

Switched Network

Communication between distant stations/ end-devices is typically done over a network of switching nodes.

Circuit Switching

Dedicated communication path between two stations between three phases: Establish, Transfer, and Disconnect.

Packet Switching

Station breaks long message into packets and are sent out to the network sequentially, one at a time

Datagram

Each packet treated independently and can take any practical route

Virtual Circuit

Preplanned route established before any packets sent and each packet contains a virtual circuit identifier instead of destination address

Protocol Syntax

Data formats, signal levels

Protocol Semantics

Control information and error handling

Protocol Timing

Speed matching and sequencing

Physical Layer Function

Handles the transmission of raw bits over a communication link

Data Link Layer Function

Collects a stream of bits into a larger aggregate called a frame and frames are actually delivered to hosts.

Network Layer Function

Handles routing among nodes within a packet-switched network and unit of data exchanged between nodes in this layer is called a packet

Transport Layer Function

Implements a process-to-process channel and unit of data exchanges in this layer is called a message

Session Layer Function

Provides a name space that is used to tie together the potentially different transport streams that are part of a single application

Presentation Layer Function

Concerned about the format of data exchanged between peers

Application Layer Function

Standardize common type of exchanges

Network Interface Layer

Is the interface to the actual network hardware. This interface may or may not provide reliable delivery, and may be packet or stream oriented

Application Layer

Provided by the program that uses TCP/IP for communication and the interface between the application and transport layers is defined by port numbers and sockets

Transport Layer

Provides the end-to-end data transfer by delivering data from an application to its remote peer. Multiple applications can be supported simultaneously

Internetwork layer (IP / Network Layer)

Provides the virtual network image of an internet (this layer shields the higher levels from the physical network architecture below it.

Domain Name System (DNS)

A system used for translating names of domains into IP addresses.

File Transfer Protocol (FTP)

A reliable, connection-oriented service that uses TCP to transfer files between systems that support FTP.

Trivial File Transfer Protocol (TFTP)

A connectionless service that uses User Datagram Protocol (UDP) and is used on routers to transfer configuration files and Cisco IOS images

Simple Mail Transport Protocol (SMTP)

E-mail servers communicate with each other using this to send and receive mail.

Simple Network Management Protocol (SNMP)

An application layer protocol that facilitates the exchange of management information between network devices.