1: Internet & Its UsesWorking at a Small-Medium Business or ISP

What is the

Internet?

Back to the Future• Internet is a network of networks• Originally for military, science research• Available to consumers in 1991• New applications/uses being developed

Standards

Follow That Standard• New standards developed, tracked &

approved in RFC document• Allows development of different devices to

connect to Internet

Connect Me!• You connect to ISP

– Remember the ISP services?

Which ISP?

ISPs

Internet Delivery 1

Internet Delivery 2

Metro Ethernet

Select Carefully• Does the ISP have the right services?• Will it meet the growth of the company?

– Example: PatNet ISP offers $5/month & 5 email addresses to Fisher Realty

– What if 2 years from now Fisher Realty has an office with 12 employees & now needs a web presence?• Switching ISP’s creates more work & hassle

U to the I…to the S…to the P• You connect to the POP

– POPs connect you to the ISP

Internet Hierarchy- IXP

Tier 1 ISP• AT&T, Sprint, Level 3 Communications

– Top of hierarchy– They interconnect privately (PEERING)– Connect at IXP– Own the fiber cables for global comm.

Sprint- Tier 1

Tier 2 ISP• Regional/National ISPs

– Connects to Tier 1 & with other Tier 2’s– Connects to IXP– Tier 2 pays Tier 1 for connectivity

Tier 3 ISP• Connects to Tier 2• Local “mom & pop” ISP (Jersey.net)

Ping & Tracert• Ping- connectivity test (echo request)

– Time it takes to travel– Whether it’s reachable

• Tracert (Windows) shows path• Traceroute (Router CLI) shows path

• Lab 1.2.3

Review• If you ping, do you (as the source) send out

an echo request or an echo reply?– Echo request

• What Tier ISP peers with others same sized ISP’s to form the backbone?– 1

• What is the name of the connection point where you connect to the ISP?– POP

Review• Which Internet service would a

medium/large business use?– Metro, T1, T3

• What can 2 things can you tell from a ping test?– Connectivity & how fast travels

• What document tracks the development of standards?– RFC

Review• Which test is this?

– Tracert• What connects the backbones?

– IXP (Internet Exchange Point)• What year did the Internet become widely

available for consumers?– 1991

ISP

Connectivity

ISP Devices- Must Haves• Needs to connect to other ISPs & handles

lots of traffic• DSLAM• CMTS• Modems for dial-up• Wireless Bridging• Border gateway routers• Servers for client services• Power Conditioning Equipment• Air Conditioners

ISP Requirements• Must be reliable & scalable

– Other wise loss of customers= no money– Device that are modular are good!

• Packet Tracer Lab 1.3.1.3

ISP Roles & Responsibilities

Activity

Review• When you ping, what does RTT mean?

– Round trip time• What does a ping send to a destination?

– Echo request• Speed of a T1 & T3?

– T1= 1.5Mbps– T3= 44Mbps

• Which Tier ISP forms the Internet backbone?– 1

Review• What interconnects the backbone?

– IXP• Bandwidth is measured in what?

– Bps (bits per second)• What is a document that tracks the

development of Internet standards?– RFC

• In what year did the Internet become widely available to consumers?– 1991

Review

1: Internet & Its UsesWorking at a Small-Medium Business or ISP