network structure elements of communication message source the channel message destination network...

Network StructureElements of

communication• message source• the channel• message destination

Networkdata or information

networks capable of carrying many different types of communications

Network StructureEnd Devices and their Role in the Network

– End devices form the interface between the human network and the underlying communications network

Examples: Computers, network printers, VoIP phones, security cameras, mobile handheld devices, etc.)

– Role of end devices: client, server or both

Network StructureIntermediary Devices and their Role in the Network

– Provides connectivity and ensures data flows across the network• Network Access Devices (Hubs, Switches, APs)• Internetworking Devices (Routers)• Communication Servers and Modems• Security Devices (Firewalls)

– The management of data as it flows through the network.

– Determine the path that messages should take through the network:• Regenerate and retransmit data signals• Maintain information about what pathways exist through the network

and internetwork• Notify other devices of errors and communication failures• Direct data along alternate pathways when there is a link failure• Classify and direct messages according to QoS priorities• Permit or deny the flow of data, based on security settings

Network TypesLocal Area Networks (LANs)

- An individual network usually spans a single geographical area (home, building or campus).

- Provides services and applications to people within a common organizational structure (small business, campus, region)

- Is usually administered by a single organization.

Network TypesWide Area Networks (WANs)

- LANs separated by geographic distance are connected by a network known as a Wide Area Network (WAN)

- Individual organizations usually lease connections through a telecommunications service provider (TSP) network.

- Although the organization maintains all of the policies and administration of the LANs at both ends of the connection, the policies within the communications service provider network

are controlled by the TSP.

Network TypesThe Internet is defined as a

global mesh of interconnected networks (internetworks).

The Internet is created by the interconnection of networks belonging to Internet Service Providers (ISPs) to provide access for millions of users all over the world.

The Intranet is a private connection of LANs and WANs that belongs to an organization, and is designed to be accessible only by the organization's members, employees, or others with authorization.

Layers with TCP/IP and OSI ModelTCP/IP Model

Layers with TCP/IP and OSI ModelCompare OSI and TCP/IP model

IP Addressing StructureEach device on a network

must be uniquely defined. At the Network layer, the packets of the communication need to be identified with the source and destination addresses of the two end systems

With IPv4, this means that each packet has a 32-bit source address and a 32-bit destination address in the Layer 3 header.

Network Architecture CharacteristicsFour characteristics that are addressed by

network architecture design– Fault tolerance– Scalability– Quality of service– Security

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Computer TerminologiesCPU - Central Processing UnitRAM - Random Access

MemoryROM - Read-Only MemoryCD-ROM driveFloppy disk driveHard disk driveBusSystem unitMotherboard (Mainboard)Expansion slotNetwork CardVideo CardSound CardParallel port and Serial port

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NIC: Network Interface Card

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Select a NICType of Network:

Ethernet, Token Ring, FDDIType of media:

Twisted-pair, Coaxial, Fiber-optic cableType of system bus:

PCI, ISA

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Web browser

Internet ConnectivityComputers connect to the internet in a

number of ways, can you list them?Dial-up (Modem)ISDNDSLCableNetwork

PC Basics (Components)Electronic components

TransistorIntegrated Circuit (IC)ResistorCapacitorConnectorLight Emitting Diode (LED)

PC Motherboard ComponentsBackplaneMemory ChipNetwork Interface Card

(NIC)Video CardSound CardParallel PortSerial PortMouse Port

Mouse PortKeyboard PortPower CordUniversal Serial Bus

(USB) Port

TCP/IP TestingPing

A protocol used to test TCP/IP ConnectivityStands for Packet Internet GroperSends multiple IP packets to destination

computer (typically 4 -packets)Will receive the same number of repliesInformation obtained will allow you to

ascertain network connectivity

IPConfig

Used to verify current IP configurationLab 1.1.6

Tracert

Traces the route traffic takes from source to destinationLab 1.1.7

Good luck in the test!