4-3 Frame Relay ????

1
??? ??????

• 4-1 ??????
• 4-2 ?????????
• 4-3 Frame Relay ????
• 4-4 ATM ????
• 4-5 PDH ????
• 4-6 SDH/SONET ????
• 4-7 HFC ????
• 4-8 ADSL ????

2
4-1 ?????? (?)

• ???? (Wide-Area Network, WAN)??
• ??????? (Network Access Provider, NAP)???????
• ??????? (Network Services Provider, NSP)?
  HiNet?SeedNet ? TANet
• ???? (Carrier Network)
• ???? (Transmission Network) 

3
4-1 ?????? (?)

• ????????
• ?????????

4
4-2 ????????? (?)

• WAN ???????
• ???????????? ISDN ???
• WAN ????
• ????????
•  PCM ????? 56 Kbps

5
4-2 ????????? (?)

• WAN ??????
• ???? (Virtual Circuit)
• ????Frame Relay ? ATM ???
• ????
• ??????? (Permanent Virtual Circuit, PVC)
• ??????? (Switched Virtual Circuit, SVC)

6
4-3 Frame Relay ????

• 1990  ?? X.25 ??????????
• ????
• ???????
• ????
• Permanent Virtual Circuit (PVC)
• Switched Virtual Circuit (SVC)
• ??/????? Data-Link Connection Identifier (DLCI)

7
4-4 ATM ???? (?)

• ATM ??????
• ?????????(Asynchronous Transfer Mode, ATM)
• ??? (??) ?????

8
4-4 ATM ???? (?)

• ATM ???????
• ATM ?????? (IP ??) ? 48 Bytes  ?????????
• ATM ??? 5 Bytes  ?????,?? 53 Bytes ????ATM ????
• ATM ?????????????SDH/SONET ?????

9
4-4 ATM ???? (?)

• VP ? VC ????
• ????????
• ???? (Virtual Channel, VC)
• ??????? (Virtual Channel Identification, VCI)
• ???? (Virtual Path, VP)
• ??????? (Virtual Path Identification, VPI)

10
4-4 ATM ???? (?)

• ??/??????
• ??/??????
• ???????(Next Hop)
• ?????? (Virtual Channel Connection, VCC)
• (600/70)?SW1?(300/200)?SW2?(100/50)?SW3?(10/30) 

11
4-4 ATM ???? (?)

• PVC ? SVC ??
• Permanent Virtual Connection (PVC)
• ???????
• ??????
• ??????
• Switched Virtual Connection (SVC)
• ?????? (Routing Protocol)
• ???? (Signaling Protocol)

12
4-4 ATM ???? (?)

• ATM ????
• ???? (Quality of Service, QoS)
• ????? (Constant Bit Rate, CBR)
• ???????? (Real-time Variable Bit Rate, RT-VBR)
• ????????? (Non-real-time Variable Bit Rate,
  NRT-VBR)
• ????? (Available Bit Rate, ABR)
• ?????? (Unspecified Bit Rate, UBR)

13
4-5 PDH ???? (?)

• ??????? (Plesiochronous Digital Hierarchy, PDH)
• ????DS-1, DS-2, DS-3, ...
• ????DS-1E, DS-2E, DS-3E, ...

14
4-5 PDH ???? (?)

• PDH ????

15
4-5 PDH ???? (?)

• PDH ????
• ??/?????? (Channel/Data Service Unit, CSU/DSU)
• ?????? (High-Speed Serial Interface, HSSI)

16
4-6 SDH/SONET ???? (?)

• SDH/SONET ??????
• ?????? (Synchronous Digital Hierarchy, SDH)
• CCITT ?? (????)
• STM-1, STM2, ...
• ?????? (Synchronous Optical Network, SONET)
• T1X1 ?? (????)
• OC1, OC2, OC3, ...
• ?????????(Synchronous Transport Signal, STS)
  ??????

17
4-6 SDH/SONET ???? (?)

• SDH/SONET ????

18
4-6 SDH/SONET ???? (?)

• SDH/SONET ????

19
4-7 HFC ???? (?)

• ???????? (Hybrid Fiber Coaxial, HFC)
• ?????????? (Wavelength Multiplexing Modulation,
  WDM)
• ????CATV ??
• ????
• ?? 10 30 Mbps
• ??3 10 Mbps
• ????? (Cable Modem)

20
4-7 HFC ???? (?)

• CATV ??
• IEEE 802.14 ??
• ???????? (Distributed Queue Dual Bus, DQDB)

21
4-8 ADSL ???? (?)

• ????????? (Asymmetric Digital Subscriber Line,
  ADSL)
• ??????? (Plain Old Telephone Service, POTS)
• ASDL Modem

22
4-8 ADSL ???? (?)

• ADSL ??????
• ????0 4KHz
• ????25 KHz 1.1 MHz
• ?????? (FDM)
• ???? (Echo Cancelling, EC)

23
4-8 ADSL ???? (?)

• QAM ????
• ??????? (Quadrature Amplitude Modulation, QAM)

24
4-8 ADSL ???? (?)

• CAP ????
• ??????????? (Carrier-less Amplitude and Phase
  Modulation, CAP)

25
4-8 ADSL ???? (?)

• DMT ????
• QAM ?????
• ??????? (Discrete Multitone Modulation, DMT)
• ????? 4.3125 KHz ??,?? 256 ????
• 1 6 ?????
• 7 38 ? 32 ?????
• 39 256 ? 218 ?????
• ???  256 QAM (?????? 8 bits) (8 bits/Hz)
• ???? 32 4 8 1024 Kbits
• ???? 218 4 8 6976 Kbits
• ? 250 4 8 8 Mbps (?? EC ?? )

26
4-8 ADSL ???? (?)

• ???????
• ???? DSL?(Rate-Adaptive DSL)
• ??????????????