S kills : none
description
Transcript of S kills : none
![Page 1: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/1.jpg)
Skills: noneConcepts: Link characteristics -- technology, length, speed, latency, jitter and packet loss rate, units of measure for amount of data and connection speed, link trends and the gap between developed and developing nations
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.
Link characteristics
![Page 2: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/2.jpg)
Where does this topic fit?
• Internet concepts– Applications– Technology (communication)– Implications
• Internet skills– Application development– Content creation– User skills
![Page 3: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/3.jpg)
Link technology
Link length
Link speed
Latency, jitter and packet loss rate
Link characteristics
Computer 1 Computer 2
![Page 4: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/4.jpg)
Wireless connection technologies
Satellite radio
Terrestrial radio
![Page 5: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/5.jpg)
Wire-line connection technologies
Copper, twisted pair (electronic)
Copper, coaxial cable (electronic)
Fiber (optical)
![Page 6: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/6.jpg)
Only use wireless links when a wired connection is not convenient or possible.
![Page 7: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/7.jpg)
Link technology
Link length
Link speed
Latency, jitter and packet loss rate
Link characteristics
Computer 1 Computer 2
![Page 8: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/8.jpg)
Link length
![Page 9: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/9.jpg)
Link technology
Link length
Link speed
Latency, jitter and packet loss rate
Link characteristics
Computer 1 Computer 2
![Page 10: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/10.jpg)
0101010101001011010010111001010101010010101010001010101010101010100101010010101010010010010010101010010001010101011101001010010101010
What are some unit of measure for …
Length? Weight?
Data?
![Page 11: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/11.jpg)
0101010101001011010010111001010101010010101010001010101010101010100101010010101010010010010010101010010001010101011101001010010101010
Units of measure for quantity
inches, meters, millimeters, miles, nanometers, light years, etc.
pounds, ounces, grams, kilograms, tons, nanograms, milligrams, etc.
bits, bytes, kilobytes, kilobits, terabits, megabits, gigabytes, etc.
![Page 12: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/12.jpg)
What are some units of measure for time?
![Page 13: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/13.jpg)
Units of measure for time
hours, days, weeks, years, centuries, seconds, microseconds, nanoseconds, and so forth
![Page 14: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/14.jpg)
Rate = quantity per unit of time
Distance traveled per unit of time
![Page 15: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/15.jpg)
Units of measure for data transmission rate
Time ?Amount of data ?Transmission rate ?
Transmission rate = amount of data per unit of time
![Page 16: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/16.jpg)
Units of measure for data transmission rate
Time secondAmount of data bitTransmission rate ?
Transmission rate = amount of data per unit of time
![Page 17: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/17.jpg)
Units of measure for data transmission rate
Time secondAmount of data bitTransmission rate bits per second
Transmission rate = amount of data per unit of time
![Page 18: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/18.jpg)
The Internet
Home
![Page 19: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/19.jpg)
Link technology
Link length
Link speed
Latency, jitter and packet loss rate
Link characteristics
Computer 1 Computer 2
![Page 20: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/20.jpg)
Latency – the time for the first packet to arrive
![Page 21: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/21.jpg)
Jitter
Distance(miles)
P1(ms)
P2(ms)
P3(ms)
P4(ms)
Avg.(ms)
Jitter(st dev)
SantiagoChile 5,585 412 346 228 225 303 92.08OxfordEngland 5,408 195 194 195 193 194 .96
Which has the lowest jitter?
![Page 22: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/22.jpg)
Packet loss rate
![Page 23: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/23.jpg)
Service level agreement
![Page 24: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/24.jpg)
Speed and ping tests
![Page 25: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/25.jpg)
The link from your home to the Internet
LAN router
ISP router
Home LAN
The Internet
?
![Page 26: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/26.jpg)
Link Typical speed
residential DSL link 3 mb/s
residential cable link 10 mb/s
residential fiber link 25 mb/s
residential satellite 1 mb/s
Link from our campus to CSU net 1 gb/s
intercity fiber 10 gb/s
undersea fiber cable 1 tb/s
Typical speed examples
![Page 28: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/28.jpg)
Steadily faster
![Page 29: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/29.jpg)
International traffic
![Page 30: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/30.jpg)
Intercontinental traffic flows
![Page 31: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/31.jpg)
Summary
Computer 1 Computer 2
![Page 32: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/32.jpg)
Self-study questions1. We discussed several characteristics of a communication link. Without looking back, do you recall what
they were?2. Name two units of measure for each of the following:
• Weight• Length• Rate at which you run• Amount of data• Rate of data transmission
3. The general form of a unit of measure for velocity is distance/time. What is the general form of a unit of measure for data transmission speed?
4. What unit of measure would you use for a quantity of water?5. What unit of measurement would you use for the rate at which water flows through a hose?6. When you walk, you typically travel at rate of about 4 miles per hour. Convert that to miles per
second.7. When you walk, you typically travel at rate of about 4 miles per hour. Convert that to feet per second.8. How many bits in a megabyte?9. How long would it take to transmit a 100 megabit file over a 100 megabit/second link?10. How long would it take to transmit a 100 megabit file over a 10 megabit/second link?11. How long would it take to transmit a 100 megabit file over a one gigabit/second link?12. How long would it take to transmit a 100 megabyte file over a 100 megabit/second link?13. How long would it take to transmit a 100 megabit file over a 100 megabyte/second link?14. How long would it take to transmit a 132 megabyte file over a 12 megabit/second link?15. What are the speed, technology, length and monthly cost of the link from your home to your Internet
service provider?16. We saw that Internet links are often asymmetric – faster in one direction than the other. Why is the
transmission rate from your ISP to your home faster than the other direction?
![Page 33: S kills : none](https://reader035.fdocuments.us/reader035/viewer/2022062310/568166ce550346895ddadce6/html5/thumbnails/33.jpg)
Resources
Test ping times: http://pingtest.net
Test data transmission rate: http://speedtest.net
A more detailed link test with hints to improve performance by adjusting TCP parameters: http://ndt.anl.gov
Current data on Verizon network performance: http://www.verizonbusiness.com/about/network/latency/
The 2010 Stanford report on Internet performance: http://www.slac.stanford.edu/xorg/icfa/icfa-net-paper-jan10/report-jan10.doc
Aladdin Nassar, Worldwide Inventory of Last-mile Bandwidths & Network Latencies: http://velocityconf.com/velocity2010/public/schedule/detail/14075
Project PingER: http://www-iepm.slac.stanford.edu/pinger/