1. Wi-Fi Structures

2. Types of Wi-Fi Network Products
Access Point
Radio transceiver (transmitter/receiver) unit that plugs into a router, switch, or hub on a home network to let wireless clients– your computers – access your wired network (and Internet connection).

3. Types of Wi-Fi Network Products
router (gateway)
Shares broadband Internet connection among all the client PCs on the network.
Only difference between wired and wireless router is the latter has the access point built in.

4. Types of Wi-Fi Network Products
router (gateway), continued...
Built in Ethernet switch allows for communication between clients, as well. Expect enough Ethernet ports to connect from 2 to 8 computers using Cat 5 cable.

5. Types of Wi-Fi Network Products1 2 3 4
Wireless Network Interface Cards (NICs)
The adapter that allows a PC to connect to the access point, and thus talk to the wireless network.
All shapes and sizes:
Internal – PC Card (Sometimes called CardBus) for laptops
Internal --PCI Card for desktops
External – USB or Ethernet-to-Wireless Adapter
Embedded (non-removable) – miniPCI, comes with laptop.

6. Other Equipment
Repeaters – used to extend the signal range of a WLAN component.
Bridge – connects two separate wired or wireless LANs

7. Basic Home Wi-Fi Network
Cable/DSL Modem
The Internet
AKA the WAN
Router
Home PC connected by Ethernet
Access Point
Second Home PC connected by Wi-Fi
Second Laptop
First Laptop

8. Basic Home Wi-Fi Network (alternate)
Cable/DSL Modem
Hub or Switch
Home PCs connected by Ethernet
The Internet
Wireless Router
Home PC via Wi-Fi
PDA
Laptop
Game Console

9. Get the LAN Talking DHCP
A Dynamic Host Configuration Protocol (DHCP) server will provide IP addresses to all the computers on the network.
Most routers include a DHCP server to serve a range of addresses.

10. Get the LAN Talking DHCP
Each computer should be set to be a DHCP client.
In Windows, set the network card’s settings to “Obtain IP address automatically.”

11. Get the LAN Talking DHCP
The router will typically be your “default gateway” to the Internet and will provide the IP address indicating that to all clients.
If your router’s IP address is , all computers using to will use that router to access the Internet.

12. Home Network- IP Addresses
Cable/DSL Modem – gets IP from your ISP,
The Internet
Router Gateway for LAN: ;
To Internet appears as
Access Point:

13. Home Networking Tip “ipconfig”
If you need to quickly find out the IP address of your computer and the router/gateway, go to a command window and type ipconfig. (winipcfg in Windows 9x)

14. Get the WLAN Talking Set up the SSID:
To connect to an access point, each client must know the Service Set Identifier (SSID) – the name of the wireless network -- of the access point and set that in its configuration utility.
CHANGE the SSID -- Vendors typically set the SSID of products to a simple, generic name, like the company name or “default”
Good Security: Pick a hard-to-guess SSID, such as a mix of letters and numbers with no obvious identifying logic.

15. Get the WLAN Talking Set the channel
Most access points run on a single channel
Set the access point channel and all the clients that associate to it will use the same channel:
NOTE: b has 14 channels worldwide and 11 in the United States, but no more than three – 1, 6, and that don’t overlap and thus don’t cause interference. This is only a problem if you’re near other WLANs.

16. Home Networking Tip “ping”
Want to find out if your computer is talking to other computers, or the Internet? Send a ping. At a DOS window, type “ping” and the IP address for a computer or a Web site.

17. Home LAN Issues

18. WAN settings
The Wide Area Network (WAN), at least when it concerns your home network, is the network connection from your Internet Service Provider or broadband Cable/DSL company.
Some ISPs require you to enter information in your router such as:
Static IP address
Domain Name Server (DNS)
Point to Point Protocol over Ethernet (PPPoE) for DSL providers, with username and password

19. Network Address Translation (NAT)
NAT lets you share the one “real” IP address provided by the ISP among multiple computers on the home LAN.
The router/gateway gets that IP address from the ISP and translates it for the other computers, working hand-in-hand with DHCP.

20. Firewall
Uses rules to filter traffic from the outside Internet to your LAN, and sometimes vice versa.
Built into many routers; also available via software installed on each computer.

21. IP Ports Not the physical jacks on the back of the PC...
Each port number Identifies the type of data being sent to/from a computer.
Port 80: HTTP (Hypertext Transfer Protocol, web browser traffic)
Port 25 & 110: SMTP & POP (Simple Mail Transfer Protocol & Point Of Presence, )
Port 21: FTP (File Transfer Protocol)
Port 53: DNS (Domain Name Resolution)

22. Port Forwarding
Port Forwarding associates traffic meant for a specific port on the computer and allows it through.
Setting a computer as a Web server means you forward traffic to port 80 (reserved for Web traffic) on one specific computer, based on its IP address.
Also called port mapping, pass-through, punch-through
Could require use of a “Dynamic DNS” service

23. DMZ
The Demilitarized Zone (DMZ) is the term used for a single computer on the network that is given completely unfettered access to the Internet.
Traffic can be incoming or outgoing.
Reserve for PCs that are
Web servers
Gaming systems
Use video conferencing
That computer is wide open to the Internet and hackers– keep isolated from others.

24. Universal Plug and Play (UPnP)
UPnP ( developed by Microsoft, is meant to automate connection, installation, and configuration of network products
Performs “NAT Traversal” to automatically open the ports on a PC needed to work with a routers firewall
Both router and PC must support UPnP to get the benefit
Mainly works under Windows XP for now

25. VPN Pass-Through
Virtual Private Networks (VPNs) allow people to create a direct “tunnel” connection to their corporate network. Many routers will allow you to have the tunnel “pass-through” to the Internet and on to the corporate network.
Watch for how many simultaneous tunnels are supported

26. Firmware Upgrades
Firmware is the built-in software inside of a device that defines functions and features
Updating most access points/routers requires a firmware upgrade.
Download a software file and generally install via a utility or through the Web browser interface.