1 Internet Protocol, IPI P (voice over IPVo I P ) (packetized voice) (Internet telephony) Vo I P Vo I I P I n t e r n e ti n t e r n e t s 1.1 Vo I P I (IP telephony) p a c k e t - v o i c e I P 1.2 I P 1) a b c 2) IP 3) 4) 1.2.1 I P 1. We b
2 VoIP: IP 2. D S U Time Division Multiplexing, TDM Statistical TDM, STDM S T D M 50 T D M 20 T D M 4. 8 k b p s ~ 8 k b p s T D M 64 k b p s 8 k b p s 1 / 8 3. ( t a r i ff arbitrage) Federal Communications Commission, FCC Internet Service Provider, ISP E n h a n c e d Service Provider, ESP Vo I P E S I S P E S P I S P 1-1Merrill Ly n c h [ S T U C 98 ] 50 1-1 [ S T U C 98 ] ( ) ( ). 1 4 0 1 0 0. 0. 0 5 0 3 5. 7 5 4 5. 5. 0 1 5 1 0. 7 1 3. 6.010 7. 1 9. 1. 0 3 5 2 5. 0 3 1. 8. 11 0 7 8. 6 1 0 0. 0. 0 3 0 2 1. 4 5 [STUC98] Stuck,Bart and We i n g a r t e n, M i c h a n e l,an Carriers Make Money on IP Te l e p h o n y?,b u s i n e s s Communications Review,August,1998.
1 3 E S P Vo I P E S 1 / 41 / 3 Level J a m e s C r o w e Vo I P 1 / 27 T D M S T D M [S C H M 98 ] 1-1 bit/s per dollar 1-1 Bit/s per dollar [SCHM98] S T D M T D M ( AT M ) 4. J e r r y Lucas [LUCA98] L u c a s I S P L u c a s I P I IP over xdsl 1.2.2 IP I P I P I P AT M U N I 1-2 [SCHM98]. Schmelling,Sarah and Vittore,Vince.Evolution or Revolution,Telephony,November 16,1998 [LUCA98]. Lucas, Jerry, IP Myth vs. Reality,Telestrategies, September/October, 1998.
4 VoIP: IP AT M IP IP I P I P P C I P Vo I P AT M 12 1.2.3 I P I 3 digital sigral processors, DSP D S P D S P P C D S P I P 3 (a) (b) C P U (c) 1.2.4 ( ATM) ( ATM) 1-2 IPATM Vo I P 2005
1 5 80 2 0 1.3 IP I P A p p l e t a l ki B M S N A I P I P I P P C I P I I P I P Vo I P Vo I P (Real Time Protocol, RT P ) (Media Gateway Control Protocol, MGCP) ( R e s o u r c e Reservation Protocol, RSVP)H. 323 Vo I P I P 1.4 IP I P I P I I P B e l l 1.5 VoIP I P I P
6 VoIP: IP 1.6 I P I P Vo I P 7 I P Vo I P 7 P B X I PP B X Vo I P I P AT M S O N E T ( W D M ) Vo I P ( RT P ) ( D i ff S e r v ) ( R S V P ) ( M G C P ) Vo I P Vo I P Vo I P 1.7 VoIP Vo I P Vo I Vo I P 1-3 5 1-3 ( a ) ( t e l c o )Vo I P / I P t e l c o 64 k b p sd S 0 D S 0 6 ~ 8 k b p st e l c o Vo I P D S 0 n : 1 n I P ( i n t r a n e t ) 9
1 7 1-3 ( b ) P C I P Telco VoIP Internet VoIP Telco (a) N:1 (b) PC (c) PC 1:1 VoIP 1:1 VoIP (d) 1:1 VoIP (e) PC 1-3 VoIP P C Vo I P A / D D / A P C
8 VoIP: IP P C P C P C 3 1-3 ( c ) 1-3 ( b ) 1-3 ( b ) Vo I P 1-3 ( d ) 1 : 1 Vo I P ( G. 723. 1G. 729 4 ) 1 : 1 I P I S P 1 : 1 1-3 ( e ) 1-3(c )1-3 ( d ) Vo I PP C P B X 1-3 1-3 P B X c e n t r e x 1-3 1-3 a ~ d 1.8 VoIP I P P B X / 1-4 / P B X I P ( P O T S ) Vo I P Vo I P
1 9 PBX LAN VoIP PBX 1-4 1.9 Vo I P P B X D S U C e n t r e x I n t e r n e t I P 1-5 Vo I P Vo I P call agent G a t e k e e p e r C A G L A N S O N E T LAN VoIP LEC PBX 1-4 VoIP 64 k b p s 8 k b p s L A N C A G C A C A G
10 VoIP: IP 7 C A G C A G 7 1-5 VoIP 5 electronic commerce, E-com I P Vo I P 1.10 IP ( e l e c t r o n i c 1-6 E-mailWeb
1 11 funds transter, EFT) / A m a z o n. co me * Tr a d e We b 1-6 International Data Corporation, I D C e m a i lwe b [ P O L E 98 ] I P ( i n t r a n e t )/ Vo I P Vo I I P Prudential Securities (a) (b) 1-7 [POLE98]. Poleretsky, Zoltan. Customer Interaction in an Electronic Commerce Wo r l d,b u s i n e s s Communications Review(BCR), Nortel Supplement, January, 1999.
12 VoIP: IP [ R A P P 98 ] 1-7 Vo I P 1-4 1.11 Vo I P I 1-8 I P I n t e r n e t (Reguest for Comment, RFC) P P P Vo I P S O N E T P P P Vo I P Vo I P PBX LAN VoIP ATM PPP Diffserv RSVP FDDI RTCP LAN RTP LEC SONET MAN VoIP IP NTP WAN PBX 1-8 VoIP [RAPP98]. Rappaport, David M. The Next Wave in Do-It-Yourself Customer Service.Business Communications Review (BCR), June, 1998. (bearer service) O S I (teleservices) OSI
1 13 S O N E T AT M Vo I P Vo I P F D D I Vo I P Vo I P RT P / U D P / I P 2 1 Vo I P 1.12 1-9 ABC / ABC I S P ( I D ) 1-9 A. 1A. 2 A A A. 1 A. 2 B C C. 1 B.1 C. 2 1-9
14 VoIP: IP 1.13 1-2 I P ( T C P ) 1-2 I P best eff o r t T C P 1.14 I n t e r n e t I P Black, Uyless [BLAC98]
1 15 2 1-10I P O S I I P I n t e r n e t ( P P P ) 7 4 3 2 1 V.34, 56kbit/s, T1, 1L _ 1T 1E 1S O N E T L _ 2 P P PL A P D L _ 3I P ( O S P F ) L _ 4 T C PU D P L _ 7 1.15 I P Vo I P ( a ) (b) ( c ) 1-10 L - 2 I P U D P L - 7
16 VoIP: IP M I P S 2 M I P S 64 k b p s 8 ~ 10M I P S 16 k b p s 15 ~ 20 M I P S 8 k b p s I T U - T 4 k b p s 40 M I P S ~ 45 M I P S 1.16 1. 4 1.16.1 10 1.16.2 300 m s A B A B B A ( a )( d ) ( a ) A B; (b)b A ; (c)b ; (d)a B 400 m s5 00 m s x D S L WDM
1 17 1.16.3 V B R C B V B R ( )V B R V B R / V B R V B R C B R C B R V B R V B R V B C B R V B R C B R C B 1.16.4 1-3 1-4 1-5 [ R A D I 94 ] MOS(Mean Opinion Score) M O S 3. 5 ~ 1-3 ITU-T G / / M O S G. 722G. 711G. 721G. 728 3 1-4 M O S M O S 1-5 [RADI94] Radhika R. Roy. Networking constraints in Multimedia Conferencing and the Role of ATM Networks, AT&T Technical Journal, July/August, 1994.
18 VoIP: IP 1-3 M O S ( k b p s ) k b p s* * M O S C D 1 4 11. 4 ~ 1 5 3 6 C B R 1 9 2 1 9 2 * ( ) V B R 384 192 * 1024 ~ 1536 C B R 128 128 * 1 2 8 C B R 64/ 6 4 / * ( G. 7 2 2 ) 56/ 5 6 / 4 8 4 8 P C M 64 C B R 6 4 6 4 4. 3 ( µg. 7 11 ) VBR 6 4 3 2 ~ 2 1 * A D P C M 6 4 C B R 3 2 3 2 4. 1 ( G. 7 2 1 ) L D - C E L P 6 4 C B R 1 6 1 6 4. 1 ( G. 7 2 8 ) * MOS 44.5 ** A D P C M C B R C D C E L P F M L D - C E L P M O S P C M V B R (Adaptive differential pulse code modulation) Constant bit rate (Compact disc) (Code excited predictive linear coding) (Frequency modulation) CELP (Low delay CELP) (Mean opinion score) (Pulse code modulation) ( Variable bit rate) 1-4 VBR - * * k b p s* M O S * V B R 0 2562 239. 6 4. 5 ~ 5. 0 3 6 02 8 8 1 1 4 0 0 2 3 9. 6 4. 0 ~ 4. 5 411 V B R 2 934 239. 6 3. 54. 5 30 H Z 3 847 239. 6 3. 54. 5 8 b i t sp6 4 4 8 2 2 2 3 9. 6 3. 54. 5 M P E G - 1 * ** 33 m s M O S M P E G V B R (Mean opinion score) (Motion Picture Expert Group) ( Variable bit rate)
1 19 1-5 [ R A D I 94 ] A S C I I 0. 0 2 9 2 ~ 4 2 0. 5 0. 0 1 5 0. 0 0 8 0. 0 5 9 0. 0 2 9 8. 511-0. 0 0 4-0. 0 1 5 ( 88 / 55 8 / ) 8. 5 119 0 10 ~ 20 2 0. 5 45 4. 5 180 18 ~ 9 ( 200 / - 2. 3 2 4 / ) 3 5 9 1 0 ~ 2 0 2 0. 5 1 8 0 1 8 7 0 0 7 0 8. 5 11 ~ 9 ~35 ( 400 / 2 4 / ) 1 4 3 6 1 0 ~ 2 0 2 0. 5 7 1 8 7 2 2, 8 7 2 2 8 7 8. 5 11 ~ 36 ~ 144 ( 400 / 2 4 / 5 7 4 4 1 0 ~ 2 0 2 0. 5 2 8 7 2 287 11,488 11 5 2 ( 1600 / ~ 144 ~ 575 2 4 / * ** Mbit/s 1.17 AT & T C AT V 1.18