Connecting to the Internet Through an ISP

1. Connecting to the Internet Through an ISP Networking for Home and Small Businesses – Chapter 4

2. Objectives • Explain “what is the Internet?” and how we connect to the Internet using an Internet Service Provider (ISP). • Explain how information is sent across the Internet through an ISP. • Describe and identify the components of an ISP Network Operations Center. • Identify the different types of cables and connectors for connecting the devices in a Network Operations Center. • Construct and terminate twisted pair cables and determine type of cable needed

3. 4.1.1 Explain What the Internet Is • The Internet is a network of networks that connects users in every country in the world. • Users are connected to ISPs • ISPs are connected to other ISPs

4. 4.1.2 Internet Service Providers (ISPs) • Internet Service Providers • Give users access to internet resources • Allow organizations and individuals to publish information on the internet

5. 4.1.3 The ISPs Relationship With the Internet • ISPs use a POP to provide service to end users • There are many POPs in an ISPs network

6. 4.1.4 Options for Connecting to the ISP • Identify and describe the different connection options that ISPs can provide

7. 4.1.4 Options for Connecting to the ISP • Dialup (56 Kb Modem) • Cable • Digital Subscriber Line • Leased Line (T-1) • Satellite • Cell Modem (Air Card)

8. 4.1.5 ISP Levels of Services • Various services are available (see graphic) • Most ISPs offer two different contract levels: home service or business class service. • Asymmetric • Different upload and download speeds • Used for home • Symmetric • Same upload and download speeds • Used for business

9. 4.2.1 Importance of the Internet Protocol (IP) • Must run Internet Protocol (IP) software to communicate on Internet • IP protocol is one of the TCP/IP (Transmission Control Protocol / Internet Protocol) Protocols • As Ethernet uses Frames, IP uses Packets • Each IP packet must contain a valid source and destination IP address.

10. 4.2.1 Importance of the Internet Protocol (IP) • The IP Packet (datagram) • Has a header which contains the source and destination IP addresses • IP addresses must be unique on the Internet. • Computers in homes, small businesses and other organizations obtain their IP configuration from their ISP.

11. 4.2.2 How ISPs Handle Packets • Messages are divided into packets – size between 64 to 1500 bytes for Ethernet • Downloading a single 1 MB song would require over 600 packets of 1500 bytes. • Each individual packet must have a source and destination IP address. • Packets or datagrams contain IP address and control information • IP addresses are granted to ISPs from a regional Internet registry (RIR) • RIR North America: ARIN (http://www.arin.net) • Internet Assigned Numbers Authority: responsible for IP addressing • Internet Corporation for Assigned Names and Numbers: responsible for names and IP addressing

12. 4.2.2 How ISPs Handle Packets • NOC controls the flow of traffic • Sends traffic to remote networks if necessary • Contains services: e-mail, web

13. 4.2.3 Forwarding Packets Across the Internet • ping - tests end-to-end connectivity between source and destination • traceroute - traces the route from source to destination, displays each router and 3 Round Trip Times (RTT) • Packets are sent from router to router until they reach their destination • PACKET TRACER 4.2.3.2

14. 4.3.1 Internet Cloud

15. 4.3.2 Devices in Internet Cloud DSL Access Multiplexer (DSLAM) Cable Modem Termination System (CMTS)

18. 4.3.3 Physical and Environmental Requirements • Physical requirements of a home network versus an ISP

19. 4.4.1 Common Network Cables • Twisted Pair is used for Ethernet

21. Unshielded twisted pair (UTP) is the most commonly encountered type of network cable in North America to connect hosts, workstations, and other networking devices

22. 4.4.3 Coaxial Cable • Provides improved shielding compared to UTP, so has a lower signal-to-noise ratio • More difficult to install

23. 4.4.4 Fiber Optic Cables • Provides improved shielding compared to UTP, so has a lower signal-to-noise ratio and can therefore carry more data • Used in enterprise environments and large data centers

24. 4.5.1 Cabling Standards

25. 4.5.2 UTP Cables • Identify and describe the cross-over and straight through cable pinouts and color codes

26. 4.5.2 UTP Cables • Identify and describe the cross-over and straight through cable pinouts and color codes

27. 4.5.2 UTP Cables • Identify and describe the cross-over and straight through cable pinouts and color codes

28. 4.5.3 UTP Cable Termination Lab 4.5.3.2 – Building Straight-Through and Crossover UTP Cables

29. 4.5.4 Terminating UTP at Patch Panels and Wall Jacks

30. 4.5.5 Cable Testing

31. 4.5.5 Cable Testing

32. 4.5.5 Cable Testing • Attenuation - commonly referred to as insertion loss, is a general term that refers to the reduction in the strength of a signal • Crosstalk is the leakage of signals between pairs • near the transmitting end - NEXT • measured at the receiving end of the cable – FEXT

33. 4.5.6 Cabling Best Practices • Label the cables on both ends • Use cable ties to dress cables • Use consistent cable coloring (red for crossover, blue for windows network, grey for linux network, etc) • Test ALL cables before installing in a production network • Install cable away from EMI • Follow cable standards

34. The following steps, called best practices, ensure that cable termination is successful. • 1. It is important that the type of cables and components used on a network adhere to the standards required for that network. Modern converged networks carry voice, video and data traffic on the same wires; therefore the cables used on converged networks must be able to support all these applications. • 2. Cable standards specify maximum lengths for different types of cables. Always adhere to the length restrictions for the type of cable being installed. • 3. UTP, like all copper cable, is susceptible to EMI. It is important to install cable away from sources of interference such as high-voltage cables and fluorescent lighting. Televisions, computer monitors and microwaves are other possible sources of interference. In some environments it may be necessary to install data cables in conduit to protect them from EMI and RFI.

35. The following steps, called best practices, ensure that cable termination is successful. • 4. Improper termination and the use of low quality cables and connectors can degrade the signal carrying capacity of the cable. Always follow the rules for cable termination and test to verify that the termination has been done properly. • 5. Test all cable installations to ensure proper connectivity and operation. • 6. Label all cables as they are installed, and record the location of cables in network documentation.

42. Summary • The Internet is a worldwide collection of computer networks, accessed through ISPs. • Internet Protocol (IP) controls the structure and addressing of data packets for transport through the Internet cloud. • ISP Network Operations Centers (NOCs) utilize high-end, high-speed devices with redundancy. • Home networks feature multi-function devices which perform switching and routing. • Networks use physical cabling media which must conform to standards in construction and termination. • Cabling best practices are designed to reduce attenuation and crosstalk.