2011 I/ 2 1
ISO 7 layer reference model TCP/IP ISO 7 layer reference model 5 7 2011 I/ 2 2
2011 I/ 2 3
OSI 7 Layer Reference Model 2011 I/ 2 4
Harry Nyquist (1924) Maximum data rate = 2H log 2 V (bits/s) H: low pass filter bandwidth V: discrete level of signal Claude Shannon (1948) Maximum data rate = H log 2 (1+S/N) S/N: signal-to-noise ratio 2011 I/ 2 5
IBM370 (terminal) (host computer) 300bit/sec, 1200bit/sec, etc. (differential Manchester coding etc.) 2011 I/ 2 6
X.25 IBM HDLC - Metcalfe s Ethernet Ethernet, Token Ring 1200bit/sec 1Mbps Ethernet 2011 I/ 2 7
X.25 2011 I/ 2 8
Sync. Link / HDLC / X.25 Coax / Ethernet / XNS / ARPAnet 2011 I/ 2 9
ISO/OSI TCP/IP IBM/SNA, Digital/DECnet, Xerox/XNS,. 2011 I/ 2 10
OSI 7 Layer Reference Model Physical / Data Link / Network / Transport / Session / Presentation / Application ISO/OSI (reference model) 2011 I/ 2 11
OSI 7 Layer Reference Model Layer n+1 n-sap (Service Access Point) n-pdu (Protocol Data Unit) Layer n Layer n Peer entity Layer n-1 n-pdu = Header + SDU (Service Data Unit) 2011 I/ 2 12
OSI 7 Layer Reference Model ES (End System) Application Presentation Session Transport Network Data Link Physical (Upper Layer Protocol) IS (Intermediate System) ES (End System) NFS XDR Sun RPC TCP IP IEEE802.3 Ethernet Coax Physical connection Physical connection 2011 I/ 2 13
Physical Layer (communication media) (e.g. 0: < +0.5v, 1 > 3.7v) (e.g., 2011 I/ 2 14
Data Link Layer (1) (Layer 2) Physical Layer (frame format) (MAC sub-layer) 2011 I/ 2 15
Data Link Layer (2) HDLC LAN IEEE802.x Ethernet 802.3 Token Ring 802.5 FDDI 802.9 ISDN DLL I.100 Physical layer 2011 I/ 2 16
Network Layer (1) (Layer 3) ES : End System IS : Intermediate System 2011 I/ 2 17
Network Layer (2) ES, IS 2011 I/ 2 18
Transport Layer (1) (Layer 4) End-to-End ES ES 2011 I/ 2 19
Transport Layer (2) End-to-End 2011 I/ 2 20
Session Layer (Upper Layer Protocol) 2011 I/ 2 21
Session Layer Transaction Session Transaction Logging & Roll-back operation Session Termination 2011 I/ 2 22
Presentation Layer» 1, 2, 4, less than 1 byte (6 bits),.» Little Endian / Big Endian» MSB first, LSB first 2011 I/ 2 23
Application Layer (Layer 7) SMTP (simple mail transfer protocol) MTA: sendmail, qmail, postfix, etc. MUA: Eudora, Mozilla Thunderbird, MS/Outlook, etc. 2011 I/ 2 24
2011 I/ 2 25
IBM SNA, DECNET, Xerox XNS AppleTalk, Novell Netware, NetBIOS OSI CLNP, TP4, IS-IS, X400, TCP/IP RIP, EGP/BGP, OSPF TELNET, SMTP, DNS, FTP, SNMP, NTP,. DARPA ARPAnet, MILnet 2011 I/ 2 26
OSI ISO X.500 TCP/IP IETF 2011 I/ 2 27
DECNET OSI Protocol AppleTalk TCP/IP Netware, NetBios TCP/IP Xerox XNS: IBM SNA (Legacy System) 2011 I/ 2 28
Demise of protocols MPLS J2EE,.NET, GRID. 2011 I/ 2 29
Ethernet LAN HDLC TCP/IP (TCP/IP Protocol Suite) IP TCP 2011 I/ 2 30
2011 I/ 2 31
(multiplexing) (demultiplexing) IEEE802.3 (Ethernet) IP, AppleTalk Ethernet 2011 I/ 2 32
Multiplexing Application Presentation Session FTP DNS PAP Session Manager Transport TCP UDP TP4/AppleTalk Network Data Link Physical IP IEEE802.3 Ethernet CAT/5 cable AppleTalk 2011 I/ 2 33
Demultiplexing Application Presentation Session FTP DNS PAP Session Manager Transport TCP UDP TP4/AppleTalk Network Data Link Physical IP IEEE802.3 Ethernet CAT/5 cable AppleTalk 2011 I/ 2 34
(encapsulation) (n-1) PDU = (n-1) header + (n)pdu 2011 I/ 2 35
Encapsulation Application Presentation Session Transport Network Data Link Physical 2011 I/ 2 36
2011 I/ 2 37
Network Layer Gateway ES (End System) Application Presentation Session Transport Network Data Link Physical Network layer gateway IPv4 ES (End System) Application Presentation Session Transport Network Data Link Physical Physical connection Physical connection 2011 I/ 2 38
Transport Layer Gateway ES (End System) Application Presentation Session Transport Transport layer gateway 4/6 mapping ES (End System) Application Presentation Session Transport Network IPv4 IPv6 Network Data Link Data Link Physical Physical Physical connection Physical connection 2011 I/ 2 39
Application Layer Gateway ES (End System) Application Presentation Session Application layer gateway SMTP X400 ES (End System) Application Presentation Session Transport TCP TCP Transport Network IPv4 IPv6 Network Data Link Data Link Physical Physical Physical connection Physical connection 2011 I/ 2 40
2011 I/ 2 41