Network FundamentalsChapter 1Modified by Profs. Chen and Cappellino

Objectives In this chapter, you will learn to:

Describe how networks impact our daily lives. Describe the role of data networking in the human

network. Identify the key components of any data network. Identify the opportunities and challenges posed by

converged networks. Describe the characteristics of network

architectures: fault tolerance, scalability, quality of service and security.

Install and use IRC clients and a Wiki server.

Networks supporting the way we live

____________________________ continues to increase in importance

Methods that we use to share ideas and information are constantly changing and evolving.

Early data networks were limited to exchanging character-based information between connected computer systems.

Current networks have evolved to carry _________ _______________________________ between many different types of devices.

Communications between networks almost ____________

The Global Community Technology has helped bring about

significant change How? Examples:

_______________ communities used for exchange of ideas and information

potential to increase productivity Internet can be used to:

Run businesses, Inform of/Address emergencies Support education, science, and government etc

Popular Communication Tools _____________________ _____________________

Weblogs are web pages that are easy to update and edit by anyone

Allows people to express there opinions ______________________

Wikis are web pages that groups of people can edit and view together. Whereas a blog is more of an personal journal.

Example: Wikipedia _______________________

Podcasting is an audio-based medium The audio file is placed on a website where others can download it and

play the recording ______________________

Collaboration tools give people -from all locations -the opportunity to work together on shared documents.

Networks Supporting the way we learn Courses delivered using network or

Internet resources are often called _________________ experiences, or ______________.

The Cisco Networking Academy Program, is an example of a global online learning experience.

E-learning, in the business world, increasing in acceptance as a means to provide efficient and cost-effective employee training

What are some benefits of e-learning?

Networks Supporting the way we work Initially, data networks were used by businesses to

manage to company’s ___________ info Today, networks provide a greater __________

between related functions and between different organizations

______________: ________________ in use by just ________ company

enables the company to communicate with employees ______________ in branch locations.

_________, or extended internetworks: to _______ ______________ (ie: suppliers, vendors, and customers) limited and “need to know only” _________ to corporate data

What is communication? Establishing the Rules Before beginning to communicate with each other,

we establish rules _______________________________________ ___________________________

Among the protocols that govern successful human communication are:

An __________ sender and receiver___________________ method of communicating (face-to-face, telephone, letter, photograph)

_________________ and grammar________________________ of deliveryConfirmation or ________________ requirements

The same basic techniques govern network communications

Quality of communications There are different factors governing the success of

communication through a network External Factors

_______________Complexity of network The _____________________ between the sender and the recipient The number of times the message has to be ___________________ The number of other messages being transmitted simultaneously on

the communication network The _______________________ for successful communication

Internal factors affecting the successful communication across the network include:

The size of the message Large messages may be interrupted or delayed at different points within the

network. The importance of the message

A message with a low importance or priority could be dropped if the network becomes overloaded.

NOTE: _____________________________ used to refer web pages, e-mail and other forms of communications

Communicating over networks Successful communication relies on a web of

interconnected networks. All networks have four basic elements in common:

______________ agreements or protocols to govern how the messages are sent, directed, received and interpreted

The ___________ or units of information that travel from one device to another

_________________ such as the cabling- that can transport the messages from one device to another

_________________ on the network that exchange messages with each other

The _____________ of the various elements of the network enables equipment and devices ______________________________________

Elements of a network

In this course, we will learn about a variety of messages, devices, media, and services that allow the communication of those messages.

We will also learn about the __________________, that tie these network elements together.

Elements of a network cont. Icons are commonly used to

represent networking devices.

Shown are some common devices which often originate messages that comprise our communication.

Exs: computers, servers, IP phones.

On local area networks these devices are typically connected by LAN media (wired or wireless).

Elements of a network cont. Shown are some of the most

common intermediate devices, used to direct and manage messages across the network. __________ - the most common

device for interconnecting local area networks

_________ - provides security to networks

_________________ - helps direct messages as they travel across a network

________________ - a specific type of router often found in home networks

_____________ - used to summarize a group of networking devices, the details of which may be unimportant to the discussion at hand

_________________ - one form of WAN interconnection, represented by the lightning bolt-shaped line

Could be represented by any color

Elements of a network cont.

Network connections can be wired or wireless.

Wired connections: __________________________________

telephone wire, coaxial cable, or most commonly- _________________________ ______________________________

Carries _________________ signals Medium- _______________________

Thin strands of _____________________ Carries _______________ signals

Wireless connections Medium- Earth's atmosphere, or

space Signals are microwaves.

Elements of a network See chart for service used in

network communication Also listed are the protocols

those services use The industry standard network

protocol suite (set of protocols) used in networking today is:

_____________ (Transmission Control Protocol/Internet Protocol).

_____________ protocol of the Internet

specify the formatting, addressing and routing mechanisms that ensure our messages are delivered to the correct recipient.

Elements of a network Summary: excellent example in curriculum 1.3.2 page 5

Converged Networks Separate types of networks of the past:

Traditional _______________ (POTS), _________, ____________________, and __________________ networks

In the past, each used there own medium, their own protocols, standards and technology to carry signals

Converged network- a network that _______ _________________________________________________________________

___________________ of the above networks Eliminates the need to create and maintain separate networks.

Still contains many specialized devices

Converged Network Graphic

• The fast pace at which the development of converged network applications is occurring can be attributed to the _________________ ________________

Network Architecture

Network Architecture refers to the ___________________________________ _______________________________

consider- function of the network? anticipated needs/growth of the network? etc

Four important characteristics needed in every network- see the following four slides …

____________________ A fault tolerant network is one

that ___________________ ________________________ Must recover quickly when such

a failure occurs. These networks depend on

redundant links, or paths, between the source and destination of a message.

Curcuit Switching vs Packet Switch? Which is more fault tolerant (more to come…)

________________________ A scalable network can

____________________ ______ and applications ___________ _____________________ of the service being delivered to existing users. The operation at each layer in the

network hierarchy enables users or service providers to be inserted without causing disruption to the entire network.

______________________

New (__________________) applications available to users over internetworks create higher expectations for the quality of the services. ___________________

transmissions require a higher level of consistent quality then traditional applications (of just data)

________________________ As Internet grew the need

for security grew as wellThe security and privacy of data is necessary to exchange _______________________ ____________________.

Many tools and procedures are being implemented to combat inherent security flaws in the network architecture.

In the early days of the internet, security was not a concern

The following slides consider the four important characteristics

With respect to the INTERNET…

Circuit Switched Connection-oriented Networks Process used by _______- traditional

phone Phone switching locations between

source and destination are identified. A ____________________________

through the various switching locations to use for the duration of the telephone call.

If any ________________________, the _____________________.

To reconnect, a new call must be made, and the process repeated

Once a circuit is established, even if no communication is occurring between the persons on either end of the call, the ___________________ _________________________________________________ the call.

Packet Switched Connectionless Networks

Messages can be broken into _______ Individual blocks containing addressing

information indicating both the origination point (source) and the final destination.

Each packet sent _______________ ______________________________ ____________, and can be reassembled at destination.

No reserved circuit is built between sender and receiver.

At each location (hop), a __________ __________ as to which path to use to forward the packet towards its final destination.

Which network architecture seems more fault tolerant:

Circuit Switched Networkor

Packet Switched Networkand why?

Scalable Network Architecture The Internet-a ___________________________

__________________________________ Has a ______________________ for addressing,

for naming and for connectivity of services. As a result, network traffic that is destined for local or regional services does not need to traverse to a central point for distribution.

Common services can be duplicated in different regions, thereby __________________________ _________________________ networks.

No single organization regulates the InternetOperators of the many individual networks that provide Internet connectivity follow _________ (aka ________) _______________________.

Excellent info.- see graphics on 1.4.3

Providing Quality of service Networks must provide _____________

___________, and, at times, __________ __________________

The packet-switched network architecture –while fault tolerant- ______________________

Networks need mechanisms to manage congested network traffic.

Congestion is caused when the ____________ __________________________________________________________________

Bandwidth is __________ and not always able to be increased

Providing Quality of service In order to maintain high QoS, it is sometimes

necessary to ____________ which types of data packets must be delivered at the expense of other types of packets.

_____________________ __________________________________________ ________________________

For example, communication that is time-sensitive or important would be classified higher than communication that can wait or is of lesser importance.

__________________________The characteristics of the information being communicated also affect its management.

Information might have to be queued for a period of time or dropped

The _______________________________ on the type of company

Examples of priority decisions :Time-sensitive communication - increase priority for services like ______________________.

Non time-sensitive communication - decrease priority for _______________________.

High importance to organization - increase priority for production control or __________ __________________________________

Undesirable communication - decrease priority or block unwanted activity, like ___________ ___________________________________

Providing Network Security Consequences of a network security breach could include:

______________________ resulting in loss of business ___________________________ of personal or business info/data Results:

Company intellectual property/ contract details ___________ Customer’s ____________________________, ____________________________________ in the business

There are two types of network security concerns: ________ ____________________________________.

Securing a network infrastructure: includes _________________ of _____________________________________________ to them.

Content security: refers to _______________________________ ________________ being __________________________ and the _________________________________________________.

Providing Network Security Provide Network Security in the following three ways: _________________________

Allowing only the intended and authorized recipients to read the data.

Having a strong system for ______________________, enforcing password complexity and policies

Where appropriate, _______________________ ensures confidentiality

_____________________________________Having the assurance that the ____________________ ___________________, from source (origin) to destination.

Done by use of digital signatures, hashing algorithms and checksum mechanisms

Providing Network Security ________________________

Having the ____________________________ __________ to data services for _____________.

Resources can be unavailable during a Denial of Service (DoS) attack

Help ensure availability using Network ________________ devices Desktop and server ________________ can ensure

system reliability as well as availabilityBuilding ______________________________, with few single points of failure, can reduce the impact of these threats.

This may not be practical

Where is it all going?

There are three major trends that are contributing to the future shape of complex information networks:

Increasing number of mobile users Proliferation of network capable devices

cell phones/blackberry type devices, PDAs, notebook/ ipad type devices

Expanding range of services

Biggest challenge- keeping pace with changes and demands