High Speed Computer Networks Introduction Layered Protocol Architecture

High Speed Computer Networks Introduction Layered Protocol Architecture Chapter 2 Protocols and the TCP/IP Suite 1

Course Objective l l Introducing high speed networks including gigabit networks. Design issues related to IP and TCP/IP, Network Protocols at the last mile (or local loop – scope of the course) of a communication network like ATM, Frame Relay and Ethernet networks Provide up-to-date survey of developments in the area. Performance analysis, congestion control and provision of Qo. S to different applications are also discussed. Chapter 2 Protocols and the TCP/IP Suite 2

Course Outline l l l l Protocols and the TCP/IP Suite TCP and IP Frame Relay Asynchronous Transfer Mode High-Speed LANs Queing Analysis Congestion and Traffic Management Internet Routing Chapter 1 Protocols and the TCP/IP Suite 3

Chapter 1 Protocols and the TCP/IP Suite Chapter 2 Protocols and the TCP/IP Suite 4

Introduction Layered protocol architecture l TCP/IP protocol suite l OSI reference model l Internetworking l Chapter 2 Protocols and the TCP/IP Suite 5

The Need for a Protocol Architecture When computers and/or other data processing devices exchange data, the procedures involved can be quite complex. l High degree of cooperation required between communicating systems. l Consider the example in the next slide. l Chapter 2 Protocols and the TCP/IP Suite 6

Example: File transfer l l Requires a data path to exist – Either directly or via a communication network Tasks: – Activate data communication path or inform the comm ntk of the identity of the desired destination system. – Source determines that destination is ready – ascertain its preparedness to receive data. – File transfer app at source must ascertain that the file management app at destination is ready store file for user – One or the other system must performat conversion function – if the file formats used on the two systems are incompatible. l Instead of implementing the logic for this as a single module, the task is broken up into subtasks, each of which is implemented separately. Chapter 2 Protocols and the TCP/IP Suite 7

Layered Protocol Architecture l l modules arranged in a vertical stack Each layer in stack: – Performs related subset of the functions required to communicate with another system (a peer) – Relies on lower layer for more primitive functions – Provides services to next higher layer – Communicates with corresponding peer layer of neighboring system using a protocol Chapter 2 Protocols and the TCP/IP Suite 8

Key Features of a Protocol Set of rules or conventions to exchange blocks of formatted data l Syntax: concerns the format of the data blocks. l Semantics: include control information for coordination and error handling + flow control l Timing: includes speed matching and sequencing l Chapter 2 Protocols and the TCP/IP Suite 9

OSI Reference Model Application l Presentation l Session l Transport l Network l Data link l physical l Chapter 2 Protocols and the TCP/IP Suite 10

Figure 2. 5 Chapter 2 Protocols and the TCP/IP Suite 11

TCP/IP Layers Physical l Network access l Internet l Transport l Application l Chapter 2 Protocols and the TCP/IP Suite 12

TCP and UDP l TCP: – connection-oriented – Reliable packet delivery in sequence l UDP: – connectionless (datagram) – Unreliable packet delivery – Packets may arrive out of sequence or duplicated Chapter 2 Protocols and the TCP/IP Suite 13

Figure 2. 1 Chapter 2 Protocols and the TCP/IP Suite 14

Figure 2. 2 Chapter 2 Protocols and the TCP/IP Suite 15

Operation of TCP and IP IP implemented in end systems and routers, relaying data between hosts l TCP implemented only in end systems, assuring reliable delivery of blocks of data l Each host on subnetwork has unique IP address l Each process on each process has unique IP port number l Chapter 2 Protocols and the TCP/IP Suite 16

Figure 2 -3 Chapter 2 Protocols and the TCP/IP Suite 17

Figure 2 -4 Chapter 2 Protocols and the TCP/IP Suite 18

TCP Applications SMTP: Simple Mail Transfer Protocol l FTP: File Transfer Protocol l telnet: remote login l Chapter 2 Protocols and the TCP/IP Suite 19

Internetworking Terms Communication network l Internet l Intranet l Subnetwork l End system l Intermediate system l Bridge l Router l Chapter 2 Protocols and the TCP/IP Suite 20

Routers Provide link between networks l Accommodate network differences: l – Addressing schemes – Maximum packet sizes – Hardware and software interfaces – Network reliability Chapter 2 Protocols and the TCP/IP Suite 21

Figure 2 -7 Chapter 2 Protocols and the TCP/IP Suite 22

Figure 2 -8 Chapter 2 Protocols and the TCP/IP Suite 23

Figure 2 -9 Chapter 2 Protocols and the TCP/IP Suite 24

Figure 2 -10 Chapter 2 Protocols and the TCP/IP Suite 25