4. ??VLAN?

1
?????? ??
?? 4. ??VLAN? 5. ??Broadcasting?IP Multicasting?
?????IP???????? ?IPMulticasting ???? Live
TV?NVOD??. 6. ??QoS?CoS(IEEE 802.1p / IEEE
802.1Q).
?????
??935602 ??? 935604 ??? 935625 ???
935627 ??? 935645 ??? 935651
??? 935657 ???
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4. ??VLAN?   VLAN  ??????
??????(Virtual Bridged Local Area
Networks),????????????,
??????????????????,?????????????????????
????(Logical LAN),?????????????????????,?????
????????????????????unicast?multicast?broadcast
????? ??????????,???????????????????
????????? ??????????????????????????VLAN???
?????, ?? ??????,???????????,????????????
????????? ????? 
3
5. ??Broadcasting?IP Multicasting? ?????IP ?????
????IP Multicasting ???? Live TV?NVOD??.  
????????????????, ???? (unicast), ??
(broadcast), ????? (multicast)? ??????  
1 ???? (unicast) ???????????
(destination node) ??????????
???????,?? ???Internet???????,?????????????
???????????,??????????,??????????????
? ???Broadcast?????,???????????????
?????(??)? ?????????,
???????????????.
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2. ?? (broadcast) ???????????????,
??????????????????? IP Multicasting??????????
??????????????????????? Multicast
Group,?????????????????????????,????????
???????????(??)?????????CGMP???,Multicast????????
Broadcast????,??????????????????!
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Multicasting?????????????????,????????????????????
? ????????????????????????????,???????????,?? ???
?????????????IP?,????????????Multicast Group?
?????? ??????????????, ???????????????????,???????
?? ?????????   ????????,????????,????????????
????? (Distance Vector Multicast Routing
Protocol, DVMRP),???????????????? (Multicast Open
Shortest Path First protocol, MOSPF)?
???????????? (DVMRP) ????Mrouters????
(tunnels), ?????????????????,????????Mrouters?????
???? (tunnel)? ?? (tunnels) ????? (virtual) ????
(point-to-point) ???? (link),??????Island??? ?????
???????? (tunnel)?????metric???????? (threshold
value)? Metric?????? (routing) ??? (tunnel)
???? (cost),??????? (tunnel) ????? (traffic)
??????? (threshold value) ???????????????????
(Time To Live, TTL) ??Mrouter??????,
???????????? (tunnel) ?????? Mrouter?,?? ????Mrout
er???,?????? (TTL) ???,???????????????????? ,?????
?? (bandwidth)?
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??????????????????????metric?,????????????
(routing path) ??,???????????????????????????
(MOSPF) ?? ?Dijkstra???????? (on-demand)
??????????????,? ????? (tunnels) ??,??Mrouter?????
???????????????,????? (performance)?
?????? NVOD?Near-Video-On-Demand?
??????????????????????? ??????????????????? ??????
?????????????????????????????????????? ???????????
? ???????????????????????????????? ???????????????
?????????
???????????????????????????????????????????? ?????
??????????????????????????????????????? ??????????
?? ???1.5???????,?????????3?????????? ????????????
??????????????????????1Mbps ??????, ???????30Mbps?
???????????????????????,????????? ???????
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?????????????????????????????????????,????? ?????
????????????,????????,????,????,????,?? ??????????
?????????????????????????????????? ???????????????
??,??????,??????????????????? ????,????????,??????
???????????????   ?????????????????,??????????????
DTH?IP-Multicasting?????   ???(Digital)???????,
?????????????????,??????,?? ??????????????????????
??,????????????,?????? ??????,????????????????????
????????????????? ?,??????????????????,???????????
?,?????????? ???   DTH(Direct-To-Home)???????,???
???????????,?????????? ?????,?????DVD?????????????
?????????????????? ????????????DTH????
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IP-Multicasting???,????????????,??????????????????
??? ?????,??e-learning????????Audio?Video?Data(???
?????),????? ????????????????????????????????????
??????? ????????????????,?e-learning???????,??????
???????? ??????????cashing,??????????????????????
?   ?????????????????,???????????????????????? ?
?????????????,?????????,??????????   ?????,??????
????,????Interactive IP Multicasting?????????,???
????????????????,??????/??????,????IP/TV
Viewer???? ??????????    
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????????Hi-Video????????
(?????????????)   Hi-Video???????????????????????
??????,?????512K ADSL? ?(???????),????????????????
ATM?????,??Quality of Service (QoS)???,???????????
????,????????????????????? ???????????????????????
????,????????????????, ????????????????,??????????
???????
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???? ?????? ???? (Video Conference)
????ATM???????,??Quality of Service(QoS)???,????
?????????? ??,?????????????????????????,??????????
?   ?????? (Video On Demand) ???????????(Video
Server)?,???(Client)????????????,?????? ?????? ??
???? (Multicast) ???????????,????(Live)???(Sche
dule)?????,?????????,?? ????????????
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???? 1. ???? 2. ???? 3. ???? 4.
???????? 5. ?????? 6. ????
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????   (?)???? ?????????????????????????,???????
??HiLink (ATM)????????,???Quality of
Service??,???????????? ???????????????????????????
????????,? ???????????? ???????H.320(ISDN)/H.321
(ATM)/H.323(IP)???????,????????? ?????????????????
?????????????????????? ?????????,???????????,?????
?!?????????? ??????,???????????,????????????
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(?)????????? ????????????????????,???????????????
???????? ?????????????????,????????????????????,
????? ????,????????,???????????? (?)?????? ?
?????????,???????30Kbps?3Mbps??????,????(512Kbps)
????? ??,????????????????,???????,???????(client)
???????? ??????????????????????,?????????????????
???
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(?)????(VOD) VOD??????,???Live?????????????,?????
?????????, ??????content??VOD????
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????   ????????????????1. ??????? 2. ??????
3. ??????????? 4. ????????(T.120) 5.
??????,???????? 6. ??(Transcoding)?? 7.
??????ATM QoS????????????? 8.
??H.320/H.321/H.323????,???????? 9.
??G.711/G.722/G.728???????? 10. ??????(Chair
Control)??????(Director Mode) ?????? (Voice
Activated Control) ? ?????????
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(?) ??????? ??????????????????,????,????????????
??????, ????????????????,????????? (?)??????
??????RMS??????????,??????????????????,?????? ?
?,????? (?) ??????????? ??????????????????,??
??????????,???????????,? ???????????????,????????
???????
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(?) ????????(T.120)(?) ??????,???????? (?)
??(Transcoding)?????? 1. ??????????
??H.261?H.263??????(CIF?QCIF????30fps)? 2.
???????? ??7.5????30??? (7.5fps30fps)?
3. ??????? ?????????CIF?QCIF????? 4.
???????????? ????????????G.711?G.722?G.728,?
?????????????????
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(?) ??????ATM QoS?????????????
??????HiLink???????,?HiLink??ATM????,??QoS(Quality
of Service)??, ?????????? ...
??,????????????(?) ??H.320/H.321/H.323????,?????
???(?) ??G.711/G.722/G.728???????? (?)
??????(Chair Control)??????(Director Mode) ??????
(Voice Activated Control) ??????????
???? ?????????????? ???????????
????????????,???????,????????
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(No Transcript)
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????   ????????? ?????????? ,???????????????????
??????,????????,???????,???????????????hiVideo????
,?????????! ???? ????hiVideo??????,???????????,
?????????????,??????????,?????????????????????????
???,????????,????????????,????! ????????
hiVideo????????????hiLink?????????,??????ATM????,
??????????,???????????,??????????????????! ?????
??????hiVideo????,????????????,??????????ISDN???
???,?????????!??????????????,hiVideo??????,???????
???????????
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6. ??QoS?CoS (IEEE 802.1p / IEEE 802.1Q).
Quality of Service ????(QoS)?????????????????,????
??????? QoS?????????,????????????????????????????
???
IP(Internet Protocol)????????,????????????????????
?,??? OSI?????,?TCP??????????????????????????????
,? ????????Best Effort???????????
??????????E-mail?FTP??????????????ERP??????VoIP?Vo
D? ?????????,????????????,?????????
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????????????????????????????????????????? ???????
??????????????????????????,???????? ????????????
???Traffic Shaping,Queuing,Policy Management
??Caching ???,???????????, ??????????????????????
(Consistent response time)?QoS????????? ?????????
,?????????,?????????????????
QoS??/??????,??TCP Rate Shaping?Class-based
Queuing?Fail Allocation of Bandwidth? Packet-size
Optimization???,?????????????,??????????????????
????????????????,??????????,?????????????????
???QoS????Latency(??)?Jitter(????)?Throughput(????
)?Packet Loss(????)?? Availability(????)????????
??????QoS??????
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???????QoS???????????,??????,???????????????? ???
??????,??????Int-Serv?DiffServ?MPLS?RSVP??
??QoS???????????,?????????????????,?????????? ??,
?????????????????,QoS????????????????????? ??????
?,???????????
Web Caching?????????HTTP????????,????????????Miss
ion-Critical ?Latency-Sensitive???,???????????
?????????
?????/??/????,????????(Browser),????????????????,?
? ??/???????/???????
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CoS(Class of Service),???????????????,????????
QoS (Quality of Service),??????????????????QoS?
CoS?????????? ???????,????????????,?????????????
??????, ??????(telemedicine)??????????????,????
????,???? ??,??,?????????????????????????????????
???? 10 Mbps?????????????????,???????????????,???
?? ??????????????????????????????????,??TCP?
UDP ???????????????,????????????????????????????
,??????????????????,???????????????????
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End