Connecting to the Internet through an ISP

Networking for Home & Small Business

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

• There are several organizations that help manage it– Standards– Addressing

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 access to the Internet

• Name yours & others

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

• http://www.telegeography.com/maps/index.php

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- becoming 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

Options for 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

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

End of Day One

Activity

• Complete 4.1.5-3

• Handout Research

• Go home & test your speed!

• http://reviews.cnet.com/7004-7254_7-0.html

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– Uses packets to carry data– IP carries what you do on the Internet– Contains source & destination IP address

IP Packet

• Header contains the IP addresses & control info for routers

• IP addresses MUST be unique

• ISP gets blocks of addresses– Then they manage & split them up

How an ISP handles Packets• Before hitting the Internet, your message is

divided into small packets– Downloading a 1 MB song requires over 600 packets

of 1500 bytes each

• ISP determines whether packet is for local or for remote network

NOC

• Controls traffic flow– Uses destination IP

• Has services (web hosting, email)

NOC- Monitoring

NOC- AT &T Monitoring

Network Utilities

• Ping– End-to-end

connectivity

• Traceroute– Traces path

from source to destination

– Displays each hop

Traceroute

• http://visualroute.visualware.com/

Activities

• Packet Tracer 4.2.3.2

• Lab 4.2.3.3

The Internet Cloud

• 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• Tech at home must match tech at ISP

– DSL connects to a DSLAM (access multiplexer)

– Cable Modem connects to a CMTS (termination system)

• Must have equipment to connect to other ISPs

• Must handle lots of traffic, near 100% uptime, redundant

Devices in the Cloud

Devices in the Cloud

Activity

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

Home & Business Devices

Home & Business Environment

Cables

• What’s another name for cable?– Medium– Channel

• Copper

• Fiber Optic

Network Cables

Twisted Pair Cabling• Electricity over the copper wires• Pairs twisted inside jacket• Can get EMI• Crosstalk on long runs

– 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 in LANs/Campuses

• 2000 meters

– LED– Many paths of light

• Single Mode– More $– 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- Degredation

• 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

• 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!!