Network Fundamentals Chapter 1 Modified 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 delivery Confirmation 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 well The 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 Network or Packet Switched Network and 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 Internet Operators 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 availability Building ______________________________, with few single points of failure, can reduce the impact of these threats. This may not be practical

Biggest challenge- keeping pace with changes 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