CS/Computer Networking

    1.3 The Network Core

    network edge ๋‹ค์Œ์œผ๋กœ ์ด๋ฒˆ์—๋Š” network core์— ๋Œ€ํ•ด์„œ ๋‹ค๋ฃจ์–ด๋ณด๋ ค๊ณ  ํ•œ๋‹ค. mesh of interconnected routers(์ •ํ˜•ํ™”๋œ ๊ตฌ์กฐ๊ฐ€ ์•„๋‹Œ ๊ทธ๋ฌผ๋ง์œผ๋กœ ๋˜์–ด ์žˆ์Œ) ๋„คํŠธ์›Œํฌ ์ฝ”์–ด๋Š” ์„œ๋กœ์„œ๋กœ ์—ฐ๊ฒฐ๋˜์–ด ์žˆ๋Š” ๋ผ์šฐํ„ฐ๋“ค์˜ ์ง‘ํ•ฉ์ฒด์ด๋‹ค. ๋„คํŠธ์›Œํฌ ์ฝ”์–ด์—์„œ, router๋“ค์€ interconnected๋˜์–ด end system๊ฐ„์˜ ๋ฐ์ดํ„ฐ ๊ตํ™˜์„ ๋•๋Š”๋‹ค. ๋ฐ์ดํ„ฐ๋“ค์ด ๋ฐฉ๋ฌธํ•˜๋Š” ๋„คํŠธ์›Œํฌ์ƒ์˜ ๋ชจ๋“  ์žฅ์น˜๋“ค์€ ๊ฐ๊ฐ์˜ internet protocol stack์„ ๊ฐ€์ง€๊ณ  ์žˆ๋Š”๋ฐ internet protocol stack์˜ application layer์—์„œ ์ƒ์„ฑ๋˜๋Š” message๋“ค์€ ํ˜ธ์ŠคํŠธ๋“ค์— ์˜ํ•ด ์—ฌ๋Ÿฌ ๊ฐœ์˜ ํŒจํ‚ท์œผ๋กœ ์ชผ๊ฐœ์ง„๋‹ค. ํ˜ธ์ŠคํŠธ์— ์˜ํ•ด ์ชผ๊ฐœ์ง„ ํŒจํ‚ท๋“ค์€ network core์— ์œ„์น˜ํ•œ router๋ฅผ ..

    1.2 The Network Edge

    ๋„คํŠธ์›Œํฌ๋Š” ํฌ๊ฒŒ 3๊ฐ€์ง€๋กœ ๊ตฌ์„ฑ๋˜์–ด ์žˆ๋‹ค. ๋„คํŠธ์›Œํฌ ์—ฃ์ง€(Network edge) ์—‘์„ธ์Šค ๋„คํŠธ์›Œํฌ(Access network) ๋„คํŠธ์›Œํฌ ์ฝ”์–ด(Network core) end system๋“ค์„ core์ชฝ์œผ๋กœ ์–ด๋–ป๊ฒŒ ์˜ฎ๊ธฐ๋Š” ์ง€์— ๋Œ€ํ•œ ์—‘์„ธ์Šค ๋„คํŠธ์›Œํฌ์˜ ๋ฐฉ์‹๋“ค๊ณผ Link๋ฅผ ๊ตฌ์„ฑํ•˜๋Š” physical media์— ๋Œ€ํ•œ ํฌ์ŠคํŒ…์ด๋‹ค. 1. ๋„คํŠธ์›Œํฌ ์—ฃ์ง€๋Š” ์ธํ„ฐ๋„ท์˜ ๊ฐ€์žฅ์ž๋ฆฌ์ด๋‹ค. ์—ฌ๊ธฐ์—๋Š” ์ˆ˜๋งŽ์€ end systems์ด ์กด์žฌํ•œ๋‹ค. End system์€ host์ด๋‹ค. host๋Š” ํด๋ผ์ด์–ธํŠธ๋‚˜ ์„œ๋ฒ„๋ฅผ ๋œปํ•œ๋‹ค. ์„œ๋ฒ„๋Š” data senter์— ์žˆ๋Š” ์„œ๋ฒ„๋กœ ์ƒ๊ฐํ•˜๋ฉด ๋œ๋‹ค. 2. ์—‘์„ธ์Šค ๋„คํŠธ์›Œํฌ๋Š” ๋„คํŠธ์›Œํฌ์— ์ ‘๊ทผํ•˜๊ธฐ ์œ„ํ•œ ๋„คํŠธ์›Œํฌ์ด๋‹ค. end system๋“ค์ด ์ธํ„ฐ๋„ท์„ ์‚ฌ์šฉํ•  ์ˆ˜ ์žˆ๋„๋ก ๋„์™€์ฃผ๋Š” ๋„คํŠธ์›Œํฌ๋ผ๊ณ  ๋ณด๋ฉด ๋œ๋‹ค. ์Šค๋งˆํŠธํฐ์—์„œ ์™€์ด..

    1.1. What Is the Internet?

    1. 1 What Is the Internet? Internet : Nuts-and-Bolts ๊ด€์  / a networking infrastructure(์„œ๋น„์Šค ๊ด€์ ) 1.1.1 A Nuts-and-Bolts View (Bottom-up) Nuts-and-Bolts ๊ด€์ ์œผ๋กœ ์ธํ„ฐ๋„ท์„ ์„ค๋ช…ํ•œ๋‹ค๋ฉด ์ด๋Š” ๊ธฐ๋ณธ์  ํ•˜๋“œ์›จ์–ด ๋ฐ ์†Œํ”„ํŠธ์›จ์–ด๊ฐ€ ์ธํ„ฐ๋„ท์„ ๊ตฌ์„ฑํ•˜๊ณ  ์žˆ๋‹ค๋Š” ๊ฒƒ์ด๋‹ค. laptops, smartphones, tablets, TVs, gaming consoles ๋“ฑ๊ณผ ๊ฐ™์€ ๋ชจ๋“  ๋””๋ฐ”์ด์Šค๋“ค์€ ํ˜ธ์ŠคํŠธ(hosts) ๋˜๋Š” ์—”๋“œ ์‹œ์Šคํ…œ(end systems)๋ผ๊ณ  ๋ถˆ๋ฆฐ๋‹ค. host = end systems end systems : ์ธํ„ฐ๋„ท์— ์ง์ ‘ ์—ฐ๊ฒฐ๋˜์–ด ๊ฐœ๋ณ„ ์‚ฌ์šฉ์ž๊ฐ€ ์•ก์„ธ์Šค ํ•  ์ˆ˜์žˆ๋Š” ์ธํ„ฐํŽ˜์ด์Šค๋ฅผ ๋งŒ๋“œ๋Š” ์žฅ์น˜ (= hos..