P2P???? ?????????

1
P2P?????????????????

• ?????
• FM10019 ?? ??

2
??
1.SIP??? ??SIP????????? 2.SIP???????? 3.SIP???????
??? 4.P2P SIP??????????? 5.IMS(IP?????????????) 6
.IMS?????????FMC 7.P2P?????Skype????????? 8.Skype?
??????? 9.Skype???????? 10.Skype???????
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1.SIP?????SIP?????????
???ADSL?FTTH??????????????????????????????????????
?????????? IP?????????????
IP????? ?VoIP(Voiceover IP)???????????IP?????????
IP??????????????????????
???????????????(?????)?????????????????????
4
???????
??????? (??????)
?????????
???????
No.7???
?????
??????
?????
???
???
???
????
5
IP??????
SIP???
SIP??????(??) ???????
RTP?????????
??????? D/A??
IP??????
A/D?? ?????
P2P?
????
VoIP??????
VoIP??????
SIPSession Initiation Protocol
???????????? RTPReal-time Transport Protocol
???????????????? VoIPVoice over IP
IP??????????????(IP??)
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2.SIP????????
SIP?? IETF(???????????????)???????????????????
SIP????????????? ??????? ??????????? ?????????
??????? ?????????? SIP?Web?????????????????HTTP
?SMTP(Simple Mail Transfer Protocol) ?????????????
?????
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SIP????????????????
SIP??? (?????????)
DNS
?????????
??????
???????
DNS?????
???????
SIP??? (?????)
SIP??? (???????)
SIP??? (???????)
???????
???????
??
?????????????? ?????????????? ??????????????
???
SIP?? (???? ??????)
?????????(RTP)
SIP??
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3.SIP??????????(????)
1.??(REGISTER) SIP???(?????)???????????? ???????(a
)?????SIP URI?(b)???????????? ???????? 2.???????(
INVITE) ????UA???????SIP???(????)?INVITE??????????
???????????????UA?????SIP URI?????? 3.??(???????
?????) ????UA???UA???SDP?????????????????????????
???(RTP)???????? ??????????????P2P???????? 4.????
???(BYE) BYE?????????????????????????????????BYE?
?????????????????200 OK????????????????BYE????????
??????
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SIP?????????
?????URI (?????????)
INVITE siphanako_at_tokyo.impress.com SIP/2.0
????????
????? (???????)
SIP?????
???????? (??????????)
????????
SIP/ 200 OK
???????? (???????)
????? ?? ??RFC
REGISTER ???????????? RFC 3261
INVITE ???????? RFC 3261
ACK ??????????? RFC 3261
BYE ????????(??) RFC 3261
CANCEL ?????????????? RFC 3261
OPTION ??????? RFC 3261
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SIP?????
????????? ??????????????(???????)???????????????
? ???????(??????????????????????????)???????????
????????????????????????????????? ???????????????
??????????????????????????????
????? ?????
????? ?????
????
???? ????? etc
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????????????
???????????(PA)
???????????????????????????????????
????? ????
????? ????
????????(Presentity)
?????(Watcher)
??????????????????????
?????(Fetcher) ??????????????????????1?
??????? (Subscriber) ??????????????????????
???(Poller) ?????????????????????
??????????????? ??????????
??????????????? ????????
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4.P2P SIP???????????
?????P2P???100????????????????????????????????????
?????????
P2P???????????????? ?????????
?????????????????????????????????????????????????
? ??????????????????????????? ? ??????????????????
?????????????????
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P2P SIP??????????
???
NAT
P2P SIP???????????
NAT
UA??????
P2P SIP???????
SIP
SIP UA A
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5.IMS(IP?????????????)
IMS(IP Multimedia Subsystem)
???????????????????????SIP???????????????????????
?IP????????????????????
?????
??????????????????????????????????????? ? VoIP????
??????????????????????????????????IP??????????? ??
????
IMS???????
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?3?????????????IP??IMS
????? (??)
???
????? (IP)
???????
???
???IP ????????
???????
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6.IMS?????????FMC
Ut
Rf/Ro
AS
????
Iw
Sh
Dh
Rf/Ro
Ib
ISC/Ma
Cx
Dx
Ic
Mx
??IMS
Mk
Mx
Mw
Mx
Gp
Mw
e2
Mr
Mj
Mg
Ie
Mp
Mn
Gq
Gm
RACS(????/??????????)
IP??(?????/???)
UE
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IMS????????????
?? ???? ????
CSCF Call Session Control Function ??????????????????????????P(Proxy)-CSCF?S(Serving)-CSCF?I(Interrogating)-CSCF ?????????
MGCF Media Gateway Control Function ????????????????????????????CSCF???????????ISUP(ISDN User Part)?SIP??????????????
MRFC Multimedia Resource Function Controller S-CSCF?????????????????????MRFP(Multimedia Resource Function Processor)???????????????????????????????
BGCF Breakout Gateway Control Function ???(PSTN)??????????MGCF???????? BGCF?CSCF?MGCF?BGCF???????????SIP??????
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IMS???????????
IMS??????????? ????????????????????????????????(
?????????)???????????????????
IBCF
I-CSCF
IBCF
P-CSCF
S-CSCF
IBCF
?????A
????????????
?????????(UE A)
S-CSCF
IBCF
I-CSCF
P-CSCF
?????B
?????????(UE B)
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IMS???FMC(Fixed Mobile Convergence)???
UMA Unlicensed Mobile Access ??????????????????
????????
?????
???
???
ADSL FTTH??
GSM??????????????
??LAN ????????
Wi-Fi??
????? ??????
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VCC Voice Call Continuity SIP?????????????
?????
IMS
?????
???
???
ADSL FTTH??
SIP???????? ??IP??????????
??LAN ????????
Wi-Fi??
????? ??????
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7.P2P?????Skype?????????
Skype Technologies S.A.??????????? KaZaA????????
?????????????
??????IP???Skype????????
?????? IP?? Skype
???? ????????? ????????????????????????????? ????????????????????
?????????????????? ??? ???????????????IP?????? ???????
????????? 0ABJ?????? 050 ???? (?????????0ABJ) ID
?????????? ?? ??????????????????????? ??
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8.Skype????????
Skype????????5???? ????????
?????????IP???????????????????????????? ?????????
?????????? IP????????????????????
Skype????????????????????????? ?????
Skype?????????????????????Skype???????????????????
???????????????????????? ??????
???????????????????????????????????????? ????????
??????? ??????IP????????????????????????????????
?????? Skype????????
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9.Skype????????
SIP???
SIP??????(??) ???????
RTP?????????
???????
??????? D/A??
IP??????
A/D?? ?????
P2P?
????
VoIP??????
VoIP??????
??????????????? ????????????????? ????????????
?????IP????????????????????? ???????????????Skype
?????????
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NAT???????
?????IP?????IP?1?1????????????????????????????????
?????????????
NAT?????????????2???? UDP???????????????????
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UDP??????????
IP????2 ?????2
??1
NAT???1
NAT???2
IP????1 ?????1
??2
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Skype?????
1.?? ???????????????? ??????????????? 2.??? ???
????????????????? ???????????????????????????????
?????? ????????????????????????? 3.????? ??????
????????????????? ???????????????????????????????

Skype?????????????
????Skype???????Skype???????????????? ???RSA(Rives
t,Shamir,Adleman???????????)????1024??? ???Skype??
??????????????????????????????? ?????PKI(Public
Key Infrastructure?????)??????????
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10.Skype???????
Skype Public API(Skype Public Application Program
Interface)
??????API????Skype?P2P???????????????????????????
? Skype Public API?????????????????????????????
Skype Public????
????????????? Skype?????????????PBX?????????????
??? ?????????????????????????? ????????????? Sk
ype???????????????? ??????????????????????????????
?
Skype Extra