1. The Internet

2. Internet Tiers Internet is built in layers 9 Tier One computing centers in US Many Tier Two providers connected to Tier Ones Lots of Tier Threes connected to Tier Twos If one link breaks, there are other routes from A to B

3. TCP/IP The language of the Internet Provides many services Hypertext Transport Protocol (HTTP) is one service, FTP is another We connect to Internet using TCP/IP through Internet Service Providers (ISPs)

4. Dial-up Connections Hardware: Modem or ISDN Terminal Adapter Software: Microsoft’s Dial-up Networking (DUN) Uses PPP – Point to Point Protocol (your point to another modem)

5. Modems Modulator/Demodulator: to convert digital signals to analog to run over phone lines

6. UARTs Universal Asynchronous Receiver/Transmitter Converts parallel data to serial data to parallel data External modems do not have UARTs (they use serial port, which has UART) Internal modems have on-board UART 16550A is today’s UART

7. BAUD Technically, it is one cycle per second (same as Hertz) Max baud rate over phone lines (actually phone switches) is 2400 baud It’s 56 Kbps, not 56 baud or 56 K baud 33.6 Modem is 14 bits x 2400 Baud

9. Standards V.90 is 56K down and 33.6 up V.92 is 56K down and 48 upload All of this over perfect phone wires and to an equal modem on the other end FCC limit is 54Kbps Best actual use is 48K down and 28K up (I get 32K max.) Server Me

10. Flow Control Also called Handshaking. Local flow control between modem and COM port –Software uses special characters; XON/XOFF; slower mode –Hardware uses extra wires; RTS/CTS End-to-end flow control is between modems which is handled by the modems

11. Connections Internal –ACR (Advanced Commication Riser) – AMD –CNR (Communications Network Riser) – Intel –PCI slot –PCI-e slot External –Serial port –USB port

12. Dial-up Networking Network and Internet Connections applet Will need to know ISP phone number, account name and password Use Point-to-Point Protocol (PPP) Make sure there is dial tone on line in use Make sure dial tone is plugged into Line port “No Carrier Detect(ed)” is no connection to a modem on the other end

13. ISDN Integrated Services Digital Network Up to 64 Kbps by going digital all the way to your house over Bearer (B) channel D channels carry setup and configuration at 16Kbps Can get two B channels for 128Kbps in Basic Rate Interface (BRI) Can get 23 B’s and a D for 1.544Mbps – T1

14. xDSL Asynchronous (ADSL) is 2Mbps down and 128-768 Kbps up Synchronous (SDSL) has same up and down speed – but costs Connect filters on all jacks except the one to DSL modem NIC setup is usually just DHCP now Have to be within two miles of CO 2M 56K 2 miles

15. Cable RG-6 or RG-59 cable to modem; RJ-45 connector and UTP to computer (CAT 5e) 6-100 Mbps down and 1-10 Mbps up Got a bad rap at first due to many people sharing a cable; fiber optic backbone now

16. Networking Revisited The “language” of the Internet is TCP/IP. Have to have an IP address “Upstream” of you is likely a router that hands out IP address when your modem is turned on DHCP can supply much more than just IP address

17. Satellite Used to require a dial-up modem for upload traffic Dish now handles both up and down In theory, allows you to be way out in the bush and still connect 500 Kbps down and ~50Kbps up

18. Routers Lots to choose from at Fry’s Provide firewall between you and Internet NAT – Network Address Translation: private IP’s inside and one IP outside (public)

22. Connection Sharing Internet Connection Sharing – allows sharing of (dial-up) connection Broadband (DSL and Cable): use router between modem and PCs XP’s (Internet Connection) Firewall can prevent peer-to-peer networking as can third party firewalls isp modem router pc1 pc2 pc3

24. WWW World Wide Web Runs on port 80 Servers run special software (IIS)

25. Internet Explorer Internet Options in Control Panel or Tools menu in Explorer Internet Options has no effect outside of IE General tab: home page, browsing history, searching Security tab: Zones for Internet, local intranet, trusted sites and restricted sites Privacy tab: Cookies and pop-ups Content tab: What will or will not display Connections tab: Set up connection to Internet, connect to VPN, proxy server Programs tab: Settings for browser and add-ons Advanced tab: Accessibility, browsing, international and security

27. Proxy Server A LinkSys router operates at Layer 3 of OSI model (Network layer) PS operates at layer 7 – Application layer You request the PS to request a web page

28. Email Email address: @ Need account name, password, POP3 server name and SMTP server name Should come from your ISP Have to use your ISP’s outgoing mail (SMTP) server – even for other accounts Get a “throw away” account (free) at Yahoo or Hot Mail or Google Ports: POP3=110; IMAP=143; SMTP=25

29. FTP File Transfer Protocol Ports 20 and 21 You use FTP to download my PowerPoint decks; I use it to upload decks User name and password sent in clear text; don’t use important password

30. Telnet and SSH Telnet to remotely control a server/router Clear text, again Port 23 SSH = Secure Shell; port 22 Entire connection is encrypted; looks like Telnet

31. SFTP FTP running through an SSH tunnel Can get a dedicated server and client for this

32. VoIP Voice over IP Phone calls over the network Works with DSL to cable to satellite Skype is completely proprietary Low latency (time for packet to get there) is important Adapter is built into the cable modem from Time Warner

33. Remote Desktop Programs that allow you to run another computer Also called Terminal Emulation or VNC We will do this, both Remote Desktop and Ultra-VNC later

34. Virtual Private Network An encrypted tunnel requires endpoints with dedicated IP addresses; server at one end and client at the other Can be a dedicated box (router) Point-to-point Tunneling Protocol (PPTP) Employee to home office; Routing and Remote Access Service (RRAS) on server Remote gets address on LAN

35. LDAP Lightweight Directory Access Protocol Used to do anything with Active Directory

36. SNMP Simple Network Management Protocol Enables remote query and remote configuration of just about anything on a network, provided it is SNMP-capable

37. SMB Server Message Block Tools that get PC’s names around the network NetBIOS names are gone; SMB is the reason that Network can show you all the computers on you network SAMBA emulates SMB

38. No Connectivity Rule out the network issue(s) first Ping the URL; should get an IP address and successful ping; no IP means DNS issue “Repair” connection Try another DNS server 8.8.8.8 or 8.8.4.4

39. Limited Connectivity The dreaded APIPA address: 169.254.x.x Means no DHCP server is working (check/restart router)

40. Local-only Connectivity Could be a router problem (I had to get a new one) If no external (WAN) IP address it’s time to call ISP

41. Slow Transfer Speed It’s a bandwidth issue; similar to traffic on the freeway Buy more bandwidth? QoS = Quality of Service; can limit usage by application, IP address and others; find it on router’s configuration

42. Safe Surfing Need firewall – either Windows, router or third party Need antivirus – either pay for it (Norton) or free download (AVG Free) Need antispam software (Ad-Aware, Spybot Search and Destroy) Watch what you click on!!!!