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 HANs and LANs 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 Network Components Transmission media Network adapters Navigation devices Software

8 Transmission Media Provides communications channel between nodes Forms of media (wire): – Twisted pair (copper) telephone ethernet – Coaxial cable(copper) – Fiber-optic (FIOS) – Radio wave (wireless) Bandwidth: – Data transfer rate (max) – Throughput ( actual speed

Ethernet wire UTP – unshielded twisted pair, made of copper 4 pairs of wires (8 total wires) are twisted to reduce interference (static); RJ-45 connector Compare to telephone wire which has 2 pairs of copper wires; RJ-11 connector connector Max line 328 ft, don’t bend wire a lot, lie along edges of room. Wires, and hardware need to be at same standard 1000 M = 1G It’s 6a, not 7, in Tech In Action 8e 9

10 Network Adapters (1) A device that enables communicate between nodes on network Types: – Wired network adapter (contains Ethernet port!) – Current standard is that most laptops have wired and wireless network adapters; desktops usually wired network adapter

11 Network Adapters (2) Adapter or card, interchangeable words; Types: – Internal card = Network interface cards (NIC) (A) – Network card for laptop (B) – External card = network adapter (one type is USB adapter) (C) – Wireless network card(left pic) Enables communication between nodes A B C

12 Network Navigation Devices Router: Routes data between 2 networks Switch: Routes data across one network What is referred to as a router (or wireless router) these days… – Contains the switch and – Usually contains the modem too – Usually has wired and wireless capability; comes with 4 ports – In other words, one device contains all necessary capabilities. – Repeater – Amplifies signal across longer wires

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

14 Networking Software Peer-to-Peer Software: Built into operating systems that support networking – Windows XP, Vista, Windows 7 – Mac OS, Linux Home Network Server (“server” in the name yet still used on P2P; for media files) Client/Server Software (central services and security) Network operating system (NOS) software – Windows XP Professional,(Vista Ultimate?) – Windows Server 2008 – SUSE Linux Enterprise

15 Wired, wireless speeds Comparing the Major Types of Home Networks Wired Ethernet Power-LineWireless g Wireless n Maximum data transfer rate (bandwidth) 100 Mbps to 1 Gbps 200 Mbps54 Mbps540 Mbps Relative installation and equipment costs for networking two computers $$$$

16 Wired/wireless Ethernet Network 1.Network adapter (wireless network adapter) - each node requires one to connect to router. a. Wired nodes connect w/ Ethernet wire; Wireless nodes connect with radio frequencies 2.Wireless router -- or gateway ( a wireless router also has ports for wired computers) 3.Modem (DSL or cable) 4.Optional device –Wireless Access Point – if reception is poor in parts of your house

Wireless - other Wireless router … – Connects up to 253 wireless, yet they SHARE BANDWIDTH – Contains a transceiver (transmits and receives signals) and antenna Wireless interference: – sometimes wireless networks have interference from cinderblock, other building materials, other electronic devices, Wired 1G bps (Gigabit) networks are faster (for video files, multi-player games). Otherwise consider wired for media devices (TV, etc) 17

IEEE standards IEEE – Institute of Electrical and Electronic Engineers. Set electronic standards including those for Ethernet networks standard – wired networks standard – wireless networks: – a, b ( older and < 54 M bps) – g ( = 54 M bps) – n ( 540 M bps) Rec’d - all components from same manufacturer Cards, wires, devices must match to get that corresponding speed, but backwards compatible 18

19 Create the network 1/2 1.Install a network adapter on each node, (or verify that each one has one) 2.Connect coaxial cable to cable modem (or telephone line to DSL modem). Connect PC to modem a.Verify that Internet is live on PC. If live, then connect modem and router together. And disconnect PC above and reconnect to router. 3.Connect all other nodes to router (laptops, desktops, networkable printers, tablets, etc.)

20 Create the network 2/2 4.Turn on the following in this order, waiting a few minutes in between: a.Cable/DSL modem b.Router (Then wait a few minutes.) c.All computers other nodes (PCS, printers, etc) 5.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.)

Configuring a Router to Connect to the Internet Contact ISP for special settings Access router from Web browser Enter username and password Use router’s wizard to set up connection using settings and info provided by ISP Test Internet connection speed – Speedtest.net 21

22 Secure your wireless network SECURE YOUR WIRELESS ROUTER: 1.Change SSID to unique one (and/or turn off broadcasting of it.) 2.Change default username from “admin” to a secure username you desire. And change the password. 3.Enable security protocol (WEP or newer WPA2) 4.Restrict access via MAC filtering (MAC =Media Access Control ) 5.Limit your signal range. 6.(Apply firmware upgrades – technical step)

Other Hub – a switch is a smart hub. Hub transmits signals to all nodes whereas switch transmits only to requesting nodes. New devices, television 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 23