Networking Basics

• Networking Today introduces the fundamentals of networks.

What is a Network?

• A network is defined as a group of two or more connected entities.
• This can refer to networks of people or machines, but focuses on data and information machines like computers, IP cameras, etc.

Data Network Objectives

• Data networks enable the sharing of data and information.
• These networks also allows for the sharing of resources such as printers and fax machines.
• Networks facilitate efficient communication.

Data Network Advantages

• Employing data networks reduces costs.
• Utilization of data networks saves time.
• Data networks allow easier and faster communication.

Networks and Communication

• Networks facilitate communication between people.
• Instant messaging (IM) is supported by networks.
• Weblogs (Blogs) are easy to update and edit web pages supported by networks.
• Wikis, where groups can edit and view pages together, are network-supported.
• Podcasting allows the delivery of recordings to wide audiences because of networks.
• Collaboration tools enable teamwork on shared documents via networks.

Networks and Learning/E-learning

• Online courses are accessible to students anytime, anywhere due to networks.
• Current and accurate training materials are a key benefit of online courseware.
• Training is available to a wide audience through online courseware.
• Online courseware offers consistent quality of instruction.
• Implementing Networks gives cost reduction.

Networks and Entertainment

• Online games are supported by networks.

Network Characteristics

• The two main characteristics of networks are size (area covered) and topology (physical and logical).
• Network size refers to the area a network covers, such as PAN, LAN, MAN, or WAN.
• Topology refers to the physical and logical arrangement of a network.

Network Types by Size

• Personal Area Network (PAN) spans a limited area, houses etc and connects 5 to 10 devices.
• Local Area Network (LAN) typically spans a single geographical space like a building or campus, administered by a single organization.
• Metropolitan Area Network (MAN).
• Wide Area Network (WAN) is able to connects locations separated by large geographical areas.
• Telecommunications service providers (TSPs) often interconnect LANs in a WAN.

Internet

• The Internet is a global network of interconnected networks (internetworks).
• The most widely used, publicly accessible internetwork is the Internet.
• The Internet is created by connecting networks of Internet Service Providers (ISPs).
• ISP networks connect to provide access for millions of internet users globally.

Intranet and Extranet

• Intranets are private networks used by a single company for internal communication and transactions among employees, accessible only with authorization.
• Extranets are extended internetworks providing limited corporate data access to suppliers, vendors, and customers.

Network Topology

• Physical topology refers to the physical shape of the network and how devices are connected.
• Logical topology defines how devices communicate within the network.

Physical Topologies

• BUS
• Star
• Extended Star
• Ring
• Mesh (Full or Partial)
• Tree

Logical Topologies

• BUS
• Star
• Ring
• Mesh

Network Elements

• Data networks consist of rules, medium, messages, devices, and services.

Rules and Protocols

• Establishing rules or agreements govern communication.
• Protocols, or rules, must be followed for successful message delivery.
• Successful human communication includes identified sender/receiver, communication method, common language/grammar, delivery speed/timing, and confirmation/acknowledgement.

Medium

• Copper medium includes: Twisted pair telephone wire, Coaxial cable, UTP cable.
• Optical fibers are thin glass or plastic stands that carry light signals.
• Wireless mediums include WiFi, satellites, and cellular networks.

Criteria for choosing a network medium

• Distance
• Environment
• Amount of Data
• Costs of Media

Messages

• Data sent is put into messages that cross the media from the source to the destination.

Network Devices

• End devices (hosts, peripherals, users) and intermediary devices (connecting devices) differentiate devices of a network.
• End devices include computers, laptops, servers, network printers, IP phones, IP cameras, and mobile handheld devices, etc.
• A host device can be the source or the destination of a transmitted message.
• Intermediary devices connect individual hosts to the network and can form an internetwork by connecting multiple networks.
• Connecting devices include hubs, switches, wireless access points, routers, modems, and firewalls, etc.
• NIC (LAN adapter) provides the physical network connection to the PC, media connect to the networking device through the NIC.
• Physical Port a connector or outlet on a host or other networking device.
• Interface are specialized ports on an internetworking device used to connect networks, the ports on routers are network interfaces.

Cables

• A Straight-through Cable, an Unshielded twisted pair (UTP) copper cable connects dissimilar networking devices.
• A Crossover Cable, a UTP copper cable, connects similar networking devices
• Serial Cable are Copper cables that has wide area connections.

Services

• World Wide Web (www)
• E-Mail
• Instant Messaging (IM)
• IP Telephony (IPT)

Communication Types

• Unicast communication sends data from a single source to a single destination.
• Multicast communication sends data from a single source to a group of devices.
• Broadcast communication sends data from a single source to all devices on the network.

Communication Modes

• Simplex is a mode where only one signal is transmitted in one direction.
• Half-duplex transmits data in both directions, but not simultaneously.
• Full-duplex transmits data in both directions at the same time.

Converged Networks

• Traditional telephone, radio, television, and data networks each have their own infrastructure.
• Technology now allows the consolidation of disparate networks onto a single platform that is defined as a Converged Network.
• Converged Networks remove the need to create and maintain separate networks.

Well-Designed Networks

• A well-designed network has four basic characteristics: Fault Tolerance, Scalability, Quality of Service (QoS), and Security.
• Fault tolerance enables the network to continue operating if some components fail.
• Scalability allows a network to quickly expand to support new users and applications without impacting performance for existing users.
• Quality of Service (QoS) helps the network provide good quality and uninterrupted delivery, particularly for voice and video.
• Security ensures confidentiality and restricts unauthorized access.