Transcript Cable Modem
Fundamentals of Networking Discovery 1, Chapter 4 Connecting to the Internet through an ISP Objectives • Explain what the Internet is and how we connect to it using an ISP • Explain how information is sent across the Internet through an ISP • Describe & identify the components of an ISP Network Operations Center • Identify the different types of cables and connectors for connecting the devices in the NOS • Construct & terminate twisted pair cables and determine the type of cable needed What this Chapter is About… • Every day people are online • We need to communicate • Internet Service Providers (ISP) ▫ Make this possible ▫ Web of service providers • You’ll see: ▫ Why ISP’s are necessary ▫ The Network Operations Centers What is the Internet? • Worldwide collection of computer networks, cooperating with each other to exchange information using common standards ▫ Network of networks that connects users in every country in the world • Do this through: ▫ Wireless, fiber, telephone lines, satellite & more The Internet • Who owns it? ▫ No one • What allows computers to communicate? ▫ Protocols • There are several organizations that help manage it ▫ Standards ▫ Addressing Imagine… • What would the Internet be like if no organization granted domain names? ▫ Might have 1000 www.nintendo.com sites • What other areas did standards help in? ▫ Mobile web (other browsers) ▫ Any device with browser can access Internet ▫ Use of various devices to access web Internet Organizations • ISOC Internet Society ▫ Central leadership organization • IETF Internet Engineering Task Force ▫ Proposes solutions to Internet problems ▫ Recommends protocol standards • IRTF Internet Research Task Force ▫ Researches future of Internet ▫ How to handle transmissions during disaster • IANA Internet Assigned Numbers Authority ▫ Bookkeeper of who addresses are assigned to ISP’s • What’s an ISP? ▫ Company that provides connections & support to access the Internet • You MUST go through an ISP to get on the Internet • Name yours & others ISP Services • What other services do ISP’s provide? ▫ ▫ ▫ ▫ Internet access Domain name registration Web hosting Transit to all over • Internet is a series of ISP’s connected to one another Connect to the ISP through POP • Point of Presence • Between your LAN & the ISP • Where you get the ISP’s services- closest point of connection High Speed Backbone Maps & Videos • http://www.telegeography.com/maps/index.php • Video 1- http://youtu.be/XQVzU_YQ3IQ • Video 2- http://youtu.be/v1JEuzBkOD8 • Video 3- http://youtu.be/m6qTk5WNq9E Review 1. Describe the Internet. 2. What does ISP stand for? ▫ Internet Service Provider 3. What does an ISP do? ▫ Provides connection to the Internet 4. What is the connection point between the ISP and your LAN? ▫ POP Options for Connecting to the ISP • • • • • Dial-up- slowest, telephone lines Cell Phone Modem- decently fast DSL- high speed over phone lines Cable Modem- high speed over cable lines Leased Line- high speed over dedicated digital lines, for businesses, T1 • Satellite- medium speeds Connecting to the ISP • Modem is used to connect to ISP • You may have an ISR to connect multiple computers to the modem ISP Service Levels • Home Service ▫ ▫ ▫ ▫ Slower speed Less expensive Less web space Fewer email addresses • Business Class ▫ ▫ ▫ ▫ ▫ Faster speed More expensive More web space More email addresses SLA (Service Level Agreements) Network availability terms Service response time Link Data • Data is uploaded or downloaded ▫ Define each • There are two types of services for data transfer ▫ Usually home is different than business Asymmetric Service • Download transfer rate is different from upload rate ▫ Common in homes, most Internet users ▫ Download is faster Symmetric Service • Download transfer rate is same as upload rate ▫ Common in businesses or hosting servers ▫ Great for uploading lots of video, data, graphics Which ISP? End of Day One Activity • Handout Research • Go home & test your speed HW! • http://www.speedtest.net Review 1. Name some features that a business class ISP service would offer that home service does not. 2. Describe asymmetric service. 3. Describe symmetric service. 4. What is a POP? ▫ Connection between LAN & ISP 5. What’s the high speed links that connect ISPs called? ▫ Backbone The Importance of IP • Internet Protocol ▫ IP carries what you do on the Internet With others, like TCP/IP ▫ Uses packets to carry data ▫ MUST have source & destination IP address in packet ▫ Routers read them IP Packet • Header contains the IP addresses & control info for routers ▫ Sometimes called a datagram • IP addresses MUST be unique • ISP gets blocks of addresses from Internet Registry ▫ Then they manage & split them up How an ISP handles Packets • Message is divided into smaller packets ▫ 64-1500 bytes ▫ Downloading a 1 MB song requires over 600 packets of 1500 bytes each • ISP determines whether packet is for local ISP service or for remote network NOC • Controls traffic flow ▫ Uses destination IP ▫ Passes from router to router • Has services (web hosting, email) NOC- Monitoring NOC- AT &T Monitoring Network Utilities- Ping • Ping ▫ End-to-end connectivity ▫ Round trip time ▫ ICMP echo request Network Utilities- Traceroute • Traces path from source to destination • Displays each hop • Shows where problem is • In windows, tracert Traceroute • http://visualroute.visualware.com/ Activities • Packet Tracer 4.2.3.2- Observe Packet Travel • Lab 4.2.3.3- Use ping, traceroute, visual traceroute and whois to check connectivity and IP addresses and learn more about how packets travel through the Internet. Review The Internet Cloud- 4.3.1 • Many routes to a destination ▫ Bad router- take the back road! • Cloud represents Internet or another network Devices in the Cloud • More than just routers in cloud • Technology at home must match tech at ISP ▫ DSL connects to a DSLAM (access multiplexer) ▫ Cable Modem connects to a CMTS (termination system) ▫ Analog dial-up modem access ▫ Wireless access Devices in the Cloud Devices in the Cloud- At ISP • Must have equipment to connect to other ISPs • Must handle lots of traffic, near 100% uptime, redundant Activity- NOC Equipment Review 1. A DSLAM is needed at the ISP for which technology? ▫ DSL 2. What does DSL stand for? ▫ Digital Subscriber Line 3. A CMTS is needed for which technology? ▫ Cable Modem 4. What do you need to connect to the Internet? ▫ IP Address, default Gateway, connection to a network, and an ISP to connect you ISP Equipment Requirements • Servers to provide services ▫ Need steady, reliable power ▫ UPS ISP Equipment Requirements • Air & humidity levels • Cable management ▫ Protect from damage & kept organized Review Common Network Cables • What’s another name for cable? ▫ Medium ▫ Channel • Copper • Fiber Optic • Wireless Network Cables We’ll Discuss Twisted Pair Cabling • • • • Electricity over the copper wires Pairs twisted inside jacket Can get EMI Crosstalk on long runs ▫ Signal jump cables ▫ Cat 5 has 3-4 twists per inch ▫ Makes it more resistant to interference Kinds of Twisted Pair • UTP ▫ ▫ ▫ ▫ Electricity Inexpensive Easy to install 4 pairs of wires, color coded ▫ RJ45 connector • Cat 5 & 5e ▫ 100 & 1000Mbps • Cat 6 ▫ 1000Mbps & higher Review 1. What connector is on UTP? ▫ RJ45 2. What is the high speed links called that connect ISPs? ▫ Backbone 3. A router, switch & access point all in one is called what? ▫ ISR Coax Cable • • • • Transmits electricity Better shielding than UTP Harder to install than UTP ISP uses these for CMTS Fiber Optic Cables • Transmits pulses of light • Used in big environments • Glass or plastic ▫ No EMI • High speed ▫ LAN backbone ▫ Connect ISP to Internet • 2 fibers ▫ Transmit & receive Fiber Optic Cables • Multimode ▫ Less $, used more ▫ Used in LANs/Campuses 2000 meters ▫ LED ▫ Many paths of light • Single Mode ▫ More $, faster speed ▫ Connects backbone/NOCs 3000 meters ▫ LED laser ▫ Single path of light Activity- Fiber or UTP? Cabling Standards • Specs for installing & testing cable ▫ ▫ ▫ ▫ ▫ ▫ Pinouts (order of wires) Wire sizes Shielding Cable lengths Connector types Performance limits UTP Cables • TIA/EIA ▫ 568A ▫ 568B Straight-Through Cable • 568B to 568B • Connect unlike devices ▫ Computer to Hub/Switch ▫ Switch to router port • On the PC NIC ▫ Pins 1 & 2 transmit ▫ Pins 3 & 6 receive Crossover Cable • 568A to 568B • Like Devices ▫ ▫ ▫ ▫ Switch/hub port to switch/hub port Router port to router port PC to router port PC to PC UTP Termination • RJ45 male connector • Jack is female Let’s make cables! • Straight-through • 568B to 568B • • • • • • • • White-Orange Orange White-Green Blue White-Blue Green White-Brown Brown Let’s make cables! • Crossover • 568B to 568A • Change Oranges & Greens on ONE SIDE! • • • • • • • • White-Green Green White-Orange Blue White-Blue Orange White-Brown Brown Terminating • Patch Panel ▫ Switchboard ▫ Quickly rearrange ▫ RJ45 • Jacks Lab • Terminate to a jack Testing Cables • Open ▫ Wire not in connector ▫ Break in wire • Short ▫ Copper touches another • Reversed Pair • Split Pair Other Tests- Degradation • Attenuation ▫ Measure of signal strength ▫ If message fades at destination, will not be understood • Crosstalk ▫ Signal leaks onto another pair of wires ▫ Can happen if cables are not terminated properly or low quality connectors Cabling Best Practices- Yes or No • Cable Management ▫ Keeps wires neat & organized to easily find problems ▫ Protected from damage Review • Which cable would you use: ▫ In your house? UTP ▫ Between buildings? Fiber ▫ To your cable modem? Coax ▫ Where you get a lot of EMI? Coax or fiber, NOT UTP!! Review- 10 Fundamentals of Networking Discovery 1, Chapter 3 Connecting to the Internet through an ISP