3. 3
InternetInternet 的歷史的歷史
Arpanet introduced in 1969Arpanet introduced in 1969
TCP/IP, by V. Cerf and R. Kahn, in 1974TCP/IP, by V. Cerf and R. Kahn, in 1974
Ethernet, by R. M. Metcalfe et al., in 1976Ethernet, by R. M. Metcalfe et al., in 1976
Cellular telephones in 1978Cellular telephones in 1978
PC introduced in early 1980sPC introduced in early 1980s
Proliferation of LANs and hence the Internet inProliferation of LANs and hence the Internet in
mid 1980smid 1980s
Mosaic browser in 1993 and World-Wide WebMosaic browser in 1993 and World-Wide Web
Consortium in 1994Consortium in 1994
4. 4
InternetInternet 概觀概觀 (1/2)(1/2)
InternetInternet 是由成千上萬的是由成千上萬的
通訊設備所組成,包含通訊設備所組成,包含
了了 PC,PC, 工作站工作站 ,, 伺服器伺服器
, PDA, PDA 等等 ,, 甚至是烤麵甚至是烤麵
包機也有可能參與包機也有可能參與
InternetInternet 。。
通訊用的連線可以是光通訊用的連線可以是光
纖線、銅線、無線電、纖線、銅線、無線電、
衛星等。衛星等。
RoutersRouters :負責在網路:負責在網路
中轉送資料封包中轉送資料封包
local ISP
company
network
regional ISP
router
workstation
server
mobile
5. 5
InternetInternet 概觀概觀 (2/2)(2/2)
通訊協定通訊協定 (protocols)(protocols) :控制訊息的接收和傳送。:控制訊息的接收和傳送。
– 例如:例如: TCP, IP, HTTP, FTP, PPPTCP, IP, HTTP, FTP, PPP
Internet: “network of networks”Internet: “network of networks”
– 寬鬆的階層式架構寬鬆的階層式架構
– 開放的開放的 InternetInternet 和私有的和私有的 IntranetIntranet
InternetInternet 的標準的標準
– RFC: Request for commentsRFC: Request for comments
– IETF: Internet Engineering Task ForceIETF: Internet Engineering Task Force
http://www.ietf.orghttp://www.ietf.org
23. 23
Access NetworkAccess Network
在這裡我們會介紹下列的在這裡我們會介紹下列的 access networkaccess network
– Point to point accessPoint to point access
– Cable modemCable modem
– Local area networksLocal area networks
– Wireless access networksWireless access networks
24. 24
Point to Point AccessPoint to Point Access
ModemModem 撥接:撥接: 56 Kbps56 Kbps
ISDN (Integrated Services Digital Network)ISDN (Integrated Services Digital Network) ::
128 Kbps128 Kbps
ADSL ( Asymmetric Digital Subscriber Line)ADSL ( Asymmetric Digital Subscriber Line) ::
上傳上傳 1 Mbps,1 Mbps, 下載下載 8 Mbps8 Mbps
以上頻寬均為用戶端到以上頻寬均為用戶端到 routerrouter 端的頻寬端的頻寬
36. 36
分層中的分層中的 datadata
傳送端:每一層都會加上自己的傳送端:每一層都會加上自己的 header,header, 然後送給下一層然後送給下一層
接收端:讀取這一層對應的接收端:讀取這一層對應的 header,header, 做處理後把做處理後把 headerheader
去掉送給上一層去掉送給上一層
application
transport
network
link
physical
application
transport
network
link
physical
source destination
M
M
M
M
Ht
HtHn
HtHnHl
M
M
M
M
Ht
HtHn
HtHnHl
message
segment
frame
packet