CS 2310 Chapter 4

User Datagram Protocol

(More efficient but less reliable.) This transport layer sends a message without first establishing a connection.

Transmission Control Protocol

(More reliable but less efficient.) This transport layer is said to establish a connection before sending a message. The layers at the origin and destination work together to assure that all segments of a message are successfully transmitted. It also implements flow control.

Telnet

(and Secure Shell) This is a protocol system established to allow computers to access other computers from great distances.

Server Side

(cgi, servlets, server pages, php.) These activities by the web server are performed by the server.

URL

(http://eagle.mu.edu/authors/Shakespeare/Julius_Caesar.html) This contains the protocol required to access the document; the mnemonic name of the host holding the document; the directory path indicating the location of the document within the host's file system; and the document name.

Client Side

(javascript, macromedia flash.) These activities by the browser are performed by the client.

IP Address

A pattern of 32 or 138 bits often represented in dotted decimal notation.

Open Network

A way of classifying networks whose internal operation is based on designs that are in the public domain.

Closed Network

A way of classifying networks whose internal operation is based on innovations owned and controlled by a particular entity such as an individual or a corporation.

Electronic Mail

Also known as email, this early internet application features a domain mail server which collects incoming mail and transmits outgoing mail. The mail server delivers collected incoming mail to clients via POP3 or IMAP.

Hidden Terminal Problem

Although all of the end systems can communicate with the access point, none of the end systems can hear each other.

The Internet

An internet that spans the world. The original goal was to develop a means of connecting networks that would not be disrupted by local disasters. Today this is a commercial undertaking that links a worldwide combinations of PANs, LANs, MANs, and WANs involving millions of computers.

Bus

Computers are connected via Ethernet. (network topology)

Star

Computers are connected via wireless networks with a central access point. (network topology)

Distributed Systems

Systems with parts that run on different computers.

Internet Security Risks

The Internet can lead to attacks such as malware, denial of service, and spam. However, protective measures include firewalls, spam filters, proxy servers, and antivirus software.

Public-Key Encryption

The public key is used to encrypt messages and the private key is used to decrypt messages.

N-unicast

The technique in which an internet radio station could merely establish a server that would send program messages to each of the clients who requested them.

Network Classifications

These include personal area network (PAN), local area network (LAN), metropolitan area (MAN), and wide area network (WAN).

Browsers

These present web materials to the user.

Webservers

These provide access to web documents, which are identified by URLs and are transferred using HTTP.

Application

This (1st) layer of internet software constructs the message with the address.

Transport

This (2nd) layer of internet software chops the message into packets.

Network

This (3rd) layer of internet software handles routing through the Internet.

Link

This (4th) layer of internet software handles the actual transmission of packets.

Tier-1 ISP

This Internet Service Provider consists of high-speed, high-capacity, international WANs that serve as the backbone of the Internet.

Tier-2 ISP

This Internet Service Provider is more regional in scope and is less potent in capabilities. These networks tend to be operated by companies in the communications business.

Tier-3 ISP

This Internet Service Provider provides connectivity to the Internet through wireless hotspots, telephone lines, cable/satellite systems, or fiber optics.

Hypertext

This combines internet technology with the concept of linked documents, embedding hyperlinks to other documents.

Internet Corporation for Assigned Names and Numbers

This community allocates IP addresses to ISPs who then assign those addresses within their regions and oversees the registration of domains and domain names.

Switch

This connects several compatible networks to make a bigger network.

Bridge

This connects two compatible networks to make a bigger network.

Router

This connects two incompatible networks resulting in a network of networks called an internet.

Repeater

This extends a network to make a bigger network.

Client-Server Communication

This inter-process communication involves one server and many clients where the client initiates communication and the server must execute continuously.

Peer-to-Peer Communication

This inter-process communication involves two processes communicating as equals, and can thus be short-lived.

File Transfer Protocol

This is a client/server protocol for transferring files across the internet by establishing connections between computers.

Cluster Computing

This is a distributed system in which many independent computers work closely together to provide computation or services comparable to a much larger machine.

Grid Computing

This is a distributed system that is more loosely coupled than clusters but still work together to accomplish large tasks. It can involve specialized software to make it easier to distribute data and algorithms to the machines participating in the grid.

Cloud Computing

This is a distributed system where huge pools of shared computers on the network can be allocated for use by clients as needed.

Voice-Over IP

This is a protocol in which the Internet infrastructure is used to provide voice communication similar to that of traditional telephone systems.

Simple Mail Transfer Protocol

This is a protocol used to transfer mail between mail servers as well as to send a new message from its author's local machine to the author's mail server.

HTML

This is encoded as a text file and contains tags to communicate with the browser.

Domain Name System

This looks up name servers through the DNS lookup.

CSMA/CD

This protocol is used in Ethernet, and a silent bus provides the right to introduce new messages.

CSMA/CA

This protocol is used in Wi-Fi and faces the hidden terminal problem.

Hypertext Transfer Protocol

This protocol is used to transfer hypertext documents between browsers and webservers.

Multicast

This technique features a server that transmits a message to multiple clients by means of a single address and relies on the routers in the Internet to recognize the significance of that address and to produce and forward copies of the message to the appropriate destinations.

Mnemonic Address

Used for addressing domain names.