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

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

Follow That Standard

• Internet has standards to follow too

• New standards tracked in RFC document

Connect Me!

• You connect to ISP– Remember the ISP services?

Which ISP?

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 to ISP high-speed links

Internet Hierarchy- IXP

Tier 1 ISP

• MCI, Sprint, AT&T, Cable and Wireless– Top of hierarchy– They interconnect privately (PEERING)– Connect at IXP– Own the fiber cables

Sprint- Tier 1

Tier 2 ISP

• Smaller Regional ISPs – Connects to Tier 1 & with other Tier 2’s– Connects to IXP– Tier 2 pays Tier 1 for connectivity

Tier 3 ISP

• Connect 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 test is this?

– Tracert

• What connects the backbones?– IXP (Internet Exchange Point)

• What year did the Internet become widely available for consumers?– 1991

ISP Devices

• 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