????1.IP?綽?????
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????IP?綽?????????Inte.net?綽??????綽????????壬?????Internet?? ?綽????????????????????Internet??????????????????????楨?????????????????
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????2. IP?綽????????
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????IP?綽??????????????·?????????齻????IP??Internet??Intranet?????? ?????д???????Internet?в???“?洢????”???????????????????????? ·?????????????????????????????????IP?綽????????8kbit??S?? 10kbit??S?????????齻????????????????????????????????? ?????á? Internet?????????????????????綏????????鲼????????Inte rnet???????????????????????????????????Internet???????TCP ??IPЭ????????????????????????????????
?? ??TCP??IPЭ????????? ???IP???????????????????????????????????????????????????????? ??????????????齻????????? IP Telephony????Internet?????????? ???????????????????????????????????綽???類????IPTelephony?? ?????????????????????????????????????????Internet??????Щ?????? ??????鼰????????????????罫???????????????????????????????? ??????????????????????????????????綽???磬????????????? ??????
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????3. IP?綽???????豸—?????
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?? ????????????????????????IP?????????????????????????????? ????????Internet???‘??????”??????????綽?????????????? ???????????????????·????????Circuit??switched Network???繫?? ?????綽????PSTN???????????????????綽??????????????????????齻??????Packet??Switched Network????Internet??Intranet???????????????? ???????????????????Internet Phone???У?????????????????????? ???PSTN????Internet???????????? ??????????綽??????????????????????????IPЭ????з????? ??Internet?????????·??????Internet??????????????????Internet???? ????????????飬??????綽?????????????????綽?????????????У?? ???????????????? ???????????????????????????綽?????????????????????綽??? PSTN?????????????????????????????????????????????????????????к???????????????????IP???飬?????????к???????·???? ????? ???????IP????????·???????????IP????????????????????????? ??????з????????????????????????????????????IP??????飬????????????????????????????PSTN??????????????????????? ??????? ?????????????y??????????????綽??+Internet????+????????綽??? ????Internet???????????????????綽???????????
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????4. IP?綽????????
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???????? ??????????????????????????????????·?????;????Internet???? ??????IP?綽??????????????綽??????????????????????????? ???????????????????????????????????ù?IP?綽??????????????????? ????????????????????????綽??????綽??????????????????? ????????????Internet??????????????????Internet??????·??
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????5. IP?綽???е???????????????(1)
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?? ??* IP?綽???????? Internet?綽????????ITU??T H.323?????H.323??ITU???y?????Э?? ???H.32x?е??????H.323???????IP???磨????Internet????????????????????????????????????????Э?飬?????????? ????????????? ??????????±?????л????????y???????????磨ISDN??PSTN???е????Э?飩?? H.323?????????紫???е?????????????????????????????????? ??????MCU???? * ????Э???? ????????Internet?綽???н??????????????TCP???????????? ?????????????UDP?????????????????????IETF??????????????Э ?飺 RSVP?? Resource Reservation Protocol??????????????IP????????? ????????????y????????????????????IEtF??????????????Э?? ??RSVP????RSVP???????????????????????????????????????????RSVP?? ???????QoS??Quality of Service???????IP????????QoS???????????? RSVP??H.323???????????MCU????????? IP???????·??????????????? RSVP??RFC2205??RF C2209?ж??塣 RTP??RTCP?? Real??Time Protocol??Real-Time ControlProtocol????RTP ??IETF????????????????????????Э?飬RTP??????UDP?????RTP??????? ???????????????Time Stamp???????????????????????????????? RTCP???????????RTP????Qos??Э?顣H.323?????RTP????????RTP??RCt Э???RFC1889??C1890??
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????6. IP?綽???е??????????????? (2)
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?? ??* ????????? H.323?ж????????????????IETF??????AVT?? Audio??Video Trans port??????????????л????????о???????Internet?綽?г??????????? ?????????????￡? G.711 64Kbit/s?? G722 48??64kbit/s?? G.728 16kbit/s?? G.723??G.723.1 5.3kbit??S??6.3kbit??S?? G.729??G.729A8??13kbit??s?? ???????????????????????????????Ч????????? ???????????????????????????????о????????????????м????????????IMTC??VoIP??????????????????????????????? *??????? H.323?????????????H.245?????Q.931??????????RAS????? H.245????????????????????????????????????????H.323????????? ??Щ????????????????????????????????????????????????????? ?????????????????? ?????????????Q.931?????????佨??????? RAS?????????????????????????估?????μ??RAS????????? ?????????佨?????????????????????????RAS?????
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????VOIP????????
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????IP?綽?????????
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?? ??——IP?綽???侭?á???Ч??????????????????????1995??????????????????????????????????????о????????????????????? ??????I P?綽?????????????IP?綽?????????????????????IP??????????????????????????????????????????????IP?綽???????????????? ??????Σ????????????????????????
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????——?? ?????????Σ? CTI?????????????????????????????е???????????????????????????????????????????????IP????м??ATM??????Щ????????? ?ó?? “???????”???豸??????????????????????????????????????????????鴫????????????????????罫?????????????????????????豸???
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????——?????????????????????????紫?????????????????????????????????????????????????????????????????????????ν???????????????????????????????????????????????????з?????е?????????з????????е?λ?á?
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????——??????????????????????????????????綽???????????????????“?????”??????????????????????????????Ч??????????????????????????????????????????????????????????????????????????