S. Mandayam/ CompArch2/ECE Dept./Rowan University Computer Architecture II: Specialized /02 Fall 2001 John L. Schmalzel Shreekanth Mandayam ECE Department Rowan University Lecture 3 November 1, 2001

S. Mandayam/ CompArch2/ECE Dept./Rowan UniversityPlan Data Processing & Data Communications Communications Networks Packet Switched Networks Why are we interested in this? What are we studying here? Protocols & Protocol Architecture OSI 7-Layer Protocol Architecture TCP-IP Protocol Architecture

S. Mandayam/ CompArch2/ECE Dept./Rowan University Communications Networking Router Recall

S. Mandayam/ CompArch2/ECE Dept./Rowan University TDM: Circuit Switching Message 1 Message 2 Message N Quantize & Encode Channel Message 1 Message 2 Message N Decode LPF Recall

S. Mandayam/ CompArch2/ECE Dept./Rowan University Recall: Packet Switching Packetizing Message 2 Message 3 Message 1 1H H 23 H H 21H3 H H 21H3 H Message 2 Message 3 Message 1 Depacket -izing Recall

S. Mandayam/ CompArch2/ECE Dept./Rowan University Why are we studying this? ROUTER H 2 H 2 Memory OS COM What? Protocol Data Frequency

S. Mandayam/ CompArch2/ECE Dept./Rowan University Step 1: Step 2: Step 3: …….. Protocol Sender Medium Step 1: Step 2: Step 3: …….. Protocol Receiver Message Protocols

S. Mandayam/ CompArch2/ECE Dept./Rowan University A 3-Layer Protocol Architecture File transfer application Communications service module Network access module File transfer application Communications service module Network access module Computer 1 Computer 2 Comm network Files and file transfer commands Comm related messages

S. Mandayam/ CompArch2/ECE Dept./Rowan University ISO OSI 7-Layer Model Physical Data Link Network Presentation Session Transport Application Please Do Not Touch Steve’s Pet Alligator !!! ASIDE

S. Mandayam/ CompArch2/ECE Dept./Rowan University TCP-IP Protocol Architecture Physical Network Access Internet Transport (host-to-host) Application TCP-IP Application Presentation Session Transport Network Data Link Physical OSI Hardware Firmware Software Operating system User space

S. Mandayam/ CompArch2/ECE Dept./Rowan University TCP-IP Operation Example Network access protocol #1 Physical IP TCP Host A App X App Y Network access protocol #2 Physical IP TCP Host B App X App Y Logical connection (TCP) Port or Service access point (SAP) Global network address Network 1 Network 2 IP NAP1NAP2 Router J Subnetwork attachment point address Logical connection

S. Mandayam/ CompArch2/ECE Dept./Rowan University TCP-IP Protocol Packet TCP header IP header Network header User Data Application Byte Stream TCP Segment IP Datagram Network Level Packet

S. Mandayam/ CompArch2/ECE Dept./Rowan University IP Header VersionIHLType of ServiceTotal Length IdentificationFlagsFragment Offset Time to LiveProtocolHeader Checksum Source Address Destination Address Options + Padding octets

S. Mandayam/ CompArch2/ECE Dept./Rowan University TCP Header Source PortDestination Port Sequence Number Acknowledgement Number Data OffsetReserved URGURG ACKACK PSHPSH RSTRST SYNSYN FINFIN Window ChecksumUrgent Pointer Options + Padding octets

S. Mandayam/ CompArch2/ECE Dept./Rowan UniversitySummary

References William Stallings, Data and Computer Communications, 5 th Edition, Prentice-Hall, Jean Walrand, Communication Networks, 2 nd Edition, WCB/McGraw- Hill, 1998.