()IP OSI ( ) (TCP/IP)TCP UDP ( ) IP + IP TCP / Web TCP/UDP IP / LAN IM xdsl/ ()
(FAX) 6bit(6556) FAX FAX ( ) UDP/TCP UDP(User Datagram Protocol) CL (Connectionless) TCP(Transmission Control Protocol) CO (Connection Oriented) Virtual Circuit UDP ftp client #048 IP Ethernet TCP transport layer network layer physical layer ftp service # UDP dns service #5 IP Ethernet # TCP telnet service
UDP UDP UDP ICMP Port Unreachable UDP NFS, TFTP, SNMP DNS, / / RTP/RTSP Real-time Transport Protocol Real Time Streaming Protocol UDP,etc. RTP/UDP VoIP DVTS TCP TCP TCP
TCP Way Handshake SYN SYN + ACK PiggyBack ACK FIN FIN FIN + ACK FIN FIN + ACK FIN + ACK FIN ACK FIN + ACK MSL(TIME_WAIT) CLOSING FIN CLOSING FIN FIN + ACK FIN + ACK CLOSING FIN+ACK FIN MSL IP TTL 0 4
RST RST *) UDP ICMP Port Unreachable ACK ACK PiggyBack ACK ACK SYN SYN PiggyBack Data+ACK FIN+ACK SYN SYN+ACK ACK ( ) 5
( ) ACK ACK 7 6 8 5 4 8 8 7 6 7 6 5 4 5 4 6
7 6 5 8 4 MSS/ MSS/ RTT Network Packet loss Back-off 64sec byte Back-off 5>, 6,, 4, 48, 60, 60, 60 (sec) TCP set 75sec 0 RST 7
telnet, rlogin, ssh http, VoIP ftp, scp TCP SYNFIN UDP : hosta host B permit hostb to hosta deny all to hosta hosta ssh permit all to hostb port= deny all to hostb : : : http : QoS: Quality of Service IPAddress, Port MPLS Cut through QoS Routing LONG FAT PIPE XXXbps Advertised Window ControlCongestion Window Control Ack Network Ethernet T() T() T() OC() OC9() Bandwidth (bps) 00M.5M.5M 45M 6M 9600M RTT (ms) 60 500 60 60 60 BWxRTT (B) 7500.5 9.75 7500 4665000 7000000 8
WWW(World Wide Web) 989CERN Tim Berners-Lee HTTP(HyperText Transfer Protocol) WWW WWW Web Web HTTP Web SFC-CNS proxy.sfc.keio.ac.jp:8080 CDN Contents Distribution Network Web IP 9
CDN Japan Akamai FreeFlow 0Gbps ( ) http://www.atmarkit.co.jp/fnetwork/trend/000509/cdn.html Akamai RSS(Rich Site Summary) Akamai Web XML Blog RSS.0 RSS.0 ATOM Podcast RSS enclosure RSS MovableTypeBlog itunes Podcast RSS ipod 0
VoIP Voice Over IP IP VoIP H. SIP H. NetMeeting Polycom F45DAC4BF764D IP IP IP IP Polycom VSX6000 http://www.polycom.co.jp/products/video/vsx6000/ NetMeeting NetMeeting Windows H. [] [] conf [Enter] IP [Enter] VoIP Skype PP Kazaa NAT Skype PSTN SIP IP NTT IP IP SIP HTTP SDP RTP SIP UserAgent (SoftPhone) SIP SIP Server SIP UserAgent (SIP Phone) UserAgent SIP Server SIP UserAgent (PDA SoftPhone) PC PC SoftPhone HardPhone PDA PDA SoftPhone RGWRGW internet SIP UserAgent (RGW) SIP Server ProxyProxy Redirect Registrar Location SIP GW PSTN http://www.soi.wide.ad.jp/class/00400/slides// Softfront 004
HTTPBob REGISTER SIP-Server Server INVITE Alice Alice ProxyProxy Registrar Location REGISTER 00 OK Bob Bob Alice Alice SIP URI SIP URI SIP URI : Uniform Resource Identifier URI URL Uniform Resource LocatorsURI SIP URIsip:sips: sip:alice@example.com sips:bob@example.com mailto:alice@example.com sip: alice @ example.com ACK RTP RTP-Session http://www.soi.wide.ad.jp/class/00400/slides// Softfront 004 URI tel URI tel:+856600 http://www.soi.wide.ad.jp/class/00400/slides// Softfront 004 SIP IP http://plusd.itmedia.co.jp/broadband/005/8/l_sougo.gif () 04 5 () traceroute : /6/005 :59