1 / 31

Networks

A network comprises connected computers facilitating communication and resource sharing, such as data and printers. Key advantages include data reliability, resource sharing, and enhanced communication. Networks are classified by size (LAN/WAN), architecture (Peer-to-Peer, Client/Server), and topology (Bus, Ring, Star, Tree). Ethernet serves as the primary wired network type, allowing communication through packets. Different standards and cable types (like UTP and Fiber Optics) support varying speeds and distances. This overview provides a structured understanding of networking fundamentals.

barth
Télécharger la présentation

Networks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Networks Terminology and Hardware

  2. Network • A network is a group of connected computers that can communicate with each other to share information and equipment, such as printers.

  3. Advantages of a network • Sharing Data Reliably – without passing physical volumes, easy backup • Sharing Resources – reduces cost of buying hardware • Sharing Programs – programs can run centrally. • Communication - people can communicate and exchange messages with each other easily, effectively, and instantly. • Security Options – restricted access

  4. Networks are classified by their: • Size • Architecture • Topology

  5. Size of Networks • LAN – Local Area Network: Connects computers and devices in close proximity such as a small office or building like KRSS. • WAN – Wide Area Network: Connects a number of local area networks together over long distances (across cities, countries etc…)

  6. Architecture Configurations • Peer to Peer (p2p): People on a peer to peer network store their files on their own computers. Anyone may access files stored on any other computer. • Before the advent of TCP/IP protocols, peer to peer provided a simple and inexpensive way to connect fewer than 10 computers. (provided in Windows 98, 2000, & XP Home)

  7. Two Network Configurations • Client/Server - all files stored on a central computer. • Everyone connected to the network can access the files stored on the central server. • A Client is a computer that can access information stored on a server.

  8. Terminology Protocol – set of rules for communication Network Interface Card (NIC) – Every node is connected through an NIC – most use a 10/100 Mbps Ethernet card Node – Anything that is connected to the network (computers, printers, scanners etc…) Backbone – The main cabling of a network that all of the segments connect to. (usually faster than the connection to each NIC) Segment – Any portion of a network that is separated by a switch, bridge or router, from other parts of the network

  9. The 4 Common Wired Topologies Topology – The configuration of nodes connected to the network. • Bus – Each node is directly connected to a single central cable called a bus or backbone. • All information travels along the backbone until it reaches its destination node. • Each end must be terminated (resistor) to keep messages from bouncing back when it reaches the end of the cable.

  10. 1. Bus

  11. 2. Ring (Token Ring) • Nodes are daisy-chained. • The end of the network comes back around to the first node – completes a circuit. • Nodes take turns sending and receiving info through use of a token. • Only node with token can send info or receive info (developed by IBM).

  12. 3. Star • Star – each node is connected to a central device called a hub. The hub/concentrator takes a signal that comes from any node and passes it to all other nodes on the network.

  13. 4. Tree (Star-Bus) • The most common - combines star and bus topologies – nodes in areas are connected to hubs/concentrators (creating stars), hubs are connected together along network backbone – stars are often nested

  14. Basics of Ethernet • What it is: Currently, Ethernet is a type of wired network that connects computers and other devices. • The cables are usually copper Nodes communicate with Packets or Frames of data • Where it came from: • Originally, the material used to connect computers was ether. It was a good conductor, and it was thought that it would be less susceptible to interference. • Problem: it was too expensive

  15. Basics of Ethernet cont’d • There are practical limits to the size of the network: concerns include: • Distance limitations – electrical signals weaken as they travel. • Electrical interference scrambles signals • Practical number of devices as only one device can transmit at any given time.

  16. Ethernet Network Standards • 10BaseT • 10 Mbps • Uses UTP or CAT 5 cables • Baseband transmission – only one signal allowed on a transmission wire • 100BaseT • 100 Mbps (fast ethernet) • Use CAT5 cables – fiber optic available • Broadband – multiple signals on a single wire. • 1000BaseT – Gigabit Ethernet • 1000 Mbps - Broadband • Use CAT5e or CAT6 cables

  17. Connecting Nodes UTP - Unshielded Twisted Pair 10/100 BaseT – cheap, 100m max. STP - CAT5 – Shielded Twisted Pair – used to reduce electrical interference Coaxial Cable – must run in a ring. Fiber Optics –expensive – largest bandwidth

  18. AUI RJ45 BNC Fiber Optic 4 Types of Connectors AUI – D-shaped plug with 15 pins – common on routers and some hubs RJ45 – connectors look like big phone connectors – uses eight wires – used by most hubs and NICs BNC – small round barrel-like connectors – twist and lock together – used for coaxial Fiber Optic – usually for only one fiber optic strand

  19. CSMA/CD • CSMA/CD – Carrier Sense Multiple Access with Collision Detection • Regulates communication among nodes • Provides a “fair” set of rules for use of the line

  20. Hub (how hubs work) • Receive data • Broadcast out data on all lines • Receiving computers are responsible for listening to see if the data is for them Problems: More computers  more collisions Can’t scale more than 10 computers (Scalability) Takes more time on average for information to reach the intended node (Latency)

  21. Router (how routers work) • Receive data • Find out who the data is for • Send out data on a port that can eventually reach the intended receiver without going through a high traffic area • Keeps a table inside the router to keep track of where the high traffic areas are

  22. Switch/Bridge (how switch’s work) • LAN Switches • break hub networks into distinct segments - makes it possible for several users to send data over the network at the same time without slowing each other down • creates a series of instant networks that contain only two devices communicating with each other at that particular moment. • Nodes communicate only with the switch, so it creates a collision free environment

  23. Wireless • Bluetooth • WiFi: Wireless Fidelity - Otherwise known as Wireless Networking

  24. IEEE Standards • 802.3 – Ethernet wired standard • 802.3 is the 10 Mbps standard • 802.3u is the 100 Mbps standard • 802.3z is the 1000 Mbps standard • 802.11 – Ethernet wireless standard • 802.11b is the 11 Mbps standard • 802.11g is the 54 Mbps standard

  25. IP Address • A four part number assigned to every computer on a network • ie 192.168.1.2 • Each part of the number can be between 0-255 • A device can be manually configured to have the same address every time the device turns on • A device can be set to take an assigned number from a server or router every time it is turned on

  26. MAC Address • A six part hexadecimal number that is unique to every network card • Ie 00:02:3F:DC:75:C4 • No two network cards have the same MAC address. • The address is permanently put into the NIC at the manufacturer

  27. TCP/IP • Transmission Control Protocol/Internet Protocol • Uses IP addresses for communication • (i.e. 199.175.20.10) • Developed by ARPA (Advanced Research Projects Agency) at BB&N in 1969. • Allows for Packet Switching • Large pieces of data are broken into smaller pieces called packets • Included with each data packet is the address of the sending node and receiving devices.

  28. UDP/IP • User Datagram Protocol (UDP) • A connection-less, unreliable, transport protocol • Perfect for real time communication • Internet radio • Voice over IP (internet telephone) • Music on demand • Video conferencing • Video on demand

  29. Speeds

  30. Security • What can you do to stop someone from breaking into your system?

More Related