Chapter 7 - Networking Fundamentals

1. Chapter 7 - Networking Fundamentals • Computer network: • Two or more computers connected together • Each is a Node (other nodes: printers, network devices, such as a router, etc • Benefits of a network: • Sharing resources • Transferring files

2. Network Architecture • Network designs: • Individual PC controlled, local control • Peer-to-peer (P2P) • Central control • Client/server Peer-to-peer Client/server

3. Peer-to-Peer Networks • Use for < 10 computers for home and small office networks • Nodes communicate with each other: • Peers • Share peripheral devices: • Printers • Scanners

4. Client/Server Networks • Used for > 10 computers • Client computers: • Users • Server computers: • Provide resources to clients • Central network control • Internet • A large, multiserver, multiclient network.

5. PANs, HANs and LANs • Personal Area Network (PAN) • Connects devices close to one person (smartphones, tablets, with WiFi or Bluetooth) • Home area network (HAN) • Connects digital devices within a home • Local area network (LAN) • Nodes are within a small geographic region • Schools • Small businesses

6. WANs and MANs • Wide area network (WAN) • LANs connected over long distances • A few miles to thousands of miles • Uses telecommunications lines • Metropolitan area network (MAN) • Provides access within a specific geographic region, such as a city

7. NetworkComponents • Transmission media • Network hardware • Network Software

8. Transmission MediaOverview • Provides communications channel between nodes • Forms of media (wire): • Twisted pair (copper) • telephone • Ethernet • Coaxial cable(copper) • Fiber-optic (FIOS) • Plastic or glass fibers • Radio wave (wireless) • Bandwidth: • Data transfer rate (max) • Throughput (actual speed) Run this slide to see the pictures!

9. Transmission MediaEthernet wire Factoids • Names for Ethernet wire: • UTP – unshielded twisted pair, • “Twisted copper pairs” • It has 4 pairs of wires (8 total wires), twisted to reduce interference; RJ-45 connector • Compare to telephone wire which has 2 pairs of copper wires; RJ-11 connector • Don’t run Ethernet lines longer than 328 ft, don’t bend wire a lot, lie along edges of room.

10. Transmission MediaEthernet wire speed standards • Older: 100 M bps • Current -- for home: “1 Gigabit” = 1 G bps • = 1000 M bps • Current -- for business: 10 G bps • Wired 1G bps ( 1 Gigabit) networks are FYI the wire pictured here is NOT even Ethernet wire!!

11. Transmission MediaSpeed of common transmission media

12. Network Hardware Network Adapters (1) • Network adapter – a component on each node of the network allowing it to connect and communicate with other network nodes. • Types: • Wired network adapter (contains Ethernet port!) • Wireless network adapter (no port – its wireless!) • Current standard is that most laptops have wired and wireless network adapters; desktops usually just wired network adapter unless specially ordered

13. Network Hardware Network Adapters (2) • Adapter or card, interchangeable words; Types: • Internal version called network card = Network interface cards (NIC) • External version called network adapter (one type is USB adapter) • Same terminology used with wireless network card variety • Wired network card standard speed now is one Gigabit (1 G bps)

14. Network Hardware Network Adapters (3) Pictures of network cards and adapters: • Internal card = Network interface cards (NIC) (A) • External laptop network card; “express card” ( – goes into slot in laptop (B) • External card = network adapter (one type is USB adapter) (C) • Wireless network card(left picture) C A B

15. Network Hardware Network Navigation Devices • Router: Routes data between 2 networks • Switch: Routes data across one network. Traffic cop • A router (or wireless router) usually … • Contains the switch and • Maybe the modem too • has wired and wireless capability; comes with 4 ports • In other words, one device contains all necessary capabilities. • extender– Amplifies signal across longer wires

16. The common (wireless) router Router allows for wired and wireless connections; ports for wired connections

17. Networking Software • Peer-to-Peer Software: • Built into operating systems that support networking • Windows XP, Vista, Windows 7 • Mac OS , Linux • Client/Server Software (central services and security) • Network operating system (NOS) software • Windows Server 2008 • SUSE Linux Enterprise

18. Home network Requirements • Network adapter (wireless network adapter) - each node requires one to connect to router. • Wired nodes connect w/ Ethernet wire; Wireless nodes connect with radio frequencies (RF) • Modem (DSL or cable) • Wireless router -- or gateway ( a wireless router also has ports for wired computers) • Optional device –Wireless Access Point (or extender) – if reception is poor in parts of network • Picture next page

19. Home network picture

20. Home network Create the network 1/2 • Verify that each node on the network has a network card/adapter • Connect coaxial cable to cable modem (or telephone line to DSL modem). Connect PC to modem • Verify that Internet is live on PC. If live, then connect modem and router together. And disconnect PC above and reconnect to router. • Connect all other nodes to router (laptops, desktops, networkable printers, etc.)

21. Home network Create the network 2/2 • Turn on the following in this order , waiting a few minutes in between: • Cable/DSL modem • Router (Then wait a few minutes.) • All computers other nodes (PCS, printers, etc) • Open Control Panel> Network and Sharing. • With wired connection (and Windows 7), you should be connected to home network automatically • With wireless connection, click on Connect to a network option, (and enter security pass phrase if you already secured your router, see 2 slides ahead.)

22. IEEE standards • IEEE – Institute of Electrical and Electronic Engineers. • Set electronic standards and for Ethernet networks • 802.3 standard – wired networks • 802.11 standard – wireless networks ranked from older to newer standards: • 802.11a, b, g (older) • 802.11n • 802.11ac (newest) • (802.11ad or WiGig. Not for home networks) (newest) • When wires/hardware/technologies are paired and have differing standards, the older standard prevails, (backwards compatibility)

23. Wireless Networks • Wireless router … • Can connect up to 253 wireless • Contains a transceiver (transmits and receives signals) and antenna • Wireless • Interference - can come from cinderblock, other building materials, other electronic devices, neighbors’ networks, magnetic or electrical sources, between network equipment. • Compared to wired, wireless has lower throughput as consequence of interference

24. Wireless NetworksSECURE YOUR WIRELESS ROUTER: • Change SSID to unique one (and/or turn off broadcasting of it.) • Change default username from “admin” to a secure username you desire. And change the password. • Enable security protocol (WEP or newer WPA2) • Restrict access via MAC filtering (MAC =Media Access Control ) • Limit your signal range. • (Apply firmware upgrades – technical step)

25. Other (optional) • New devices, televisions and related media devices, now come with network adapters to connect to your network • Network attached storage (NAS) – drive accessible to network for graphic/video files • Home Network Server (“server” in the name yet still used on P2P; for media files)