Chapter 1. Introduction

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul A Brief Networking History §Internet – started from Arpanet (funded by DoD) deployed in 1969 funded by DoD packet switching – TCP/IP protocol suite by Vint Cerf & Bob Kahn in 1974 internetworking – NSFNET

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul History (cont’d) §WWW (World Wide Web) l over the Internet l distributed hypermedia technology by CERN in 1989 l WWW by CERN in 1991 l Mosaic by NCSA Center at UIUC in 1992

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul History (cont’d) §ISDN (Integrated Services Digital Network) l standardized by ITU-T: I series l standardization activity started in 1977 l widespread deployment in the early to mid- 1990s l Frame Relay streamlined form of packet switching suitable for higher-speed networks, up to about 2Mbps

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul History (cont’d) §B-ISDN (Broadband-ISDN) l standardized by ITU-T l standardization activity started in 1988 l adopt ATM as its transfer mode packet-based transport mechanism l ATM Forum formed to accelerate the development of ATM standards active participation from manufacturers

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul IP-based Internet §Key technologies l TCP/IP IP for internet routing and delivery TCP for reliable end-to-end transport UDP, RTP l dynamic routing no preconfigured routes scalability, flexibility l packet switching l Ethernet

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul Internet (cont’d) §New requirements l support of multimedia and real-time traffic l new protocols IPv6 (IP version 6) –new version of IP to expand Internet address space RSVP (Resource ReSerVation Protocol) –reserve capacity and specify the requirements of the traffic RTP (Real-time Transport Protocol) –mechanism for delivering real-time traffic multicast routing protocols

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul ATM Networks §provide efficient high-speed service scalable to virtually any data rate §seamless desktop-to-desktop connections can be created §Key technologies l internal signaling SS7 (Signaling System Number 7) define, set up, and tear down logical connections

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul ATM (cont’d) l external signaling UNI (User-Network Interface) allow user to define the expected traffic characteristics and to request network services at a particular QoS level l physical layer specification SDH (Synchronous Digital Hierarchy), SONET (Synchronous Optical NETwork) l ATM adaptation (AAL) map various upper protocols and services onto ATM layers

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul Chapter 2. Protocols and the TCP/IP Suite

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul Protocol Architecture §communication task is broken up into subtasks (layers) §a layer relies on the next lower layer to perform more primitive functions §a layer provides services to the next higher layer

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul Protocol Architecture (cont’d) §Protocol l a set of rules or conventions needed to communicate between peer layers l key features syntax - the format of data blocks semantics- control info for coordination and error handling timing - speed matching and sequencing

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul TCP/IP Protocol Architecture §TCP/IP Layers l Application layer support various user applications l Host-to-host, or transport layer provide the end-to-end reliability TCP no loss, no out-of-order l Internet layer provide routing function across multiple networks IP

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul TCP/IP Protocol Architecture (cont’d) l Internet layer (cont’d) router - a processor that connects two networks and whose primary function is to relay data from one network to the other on its route from the source to the destination end system l Network access layer concerned with the exchange of data between an end system and the network l Physical layer physical interface between a data transmission device and a transmission medium or network

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul TCP/IP Protocol Architecture (cont’d) §TCP and UDP l TCP provide a reliable connection for the transfer of data between applications l UDP provide a connectionless service for application- level procedures no guarantee on delivery, preservation of sequence, or protection against duplication

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul TCP/IP Protocol Architecture (cont’d) § IP and IPv6 l IP (IP version 4) 32-bit source and destination addresses l IPv6 (IP version 6) IPng (next-generation IP) in 1995 IPv6 in 1996 : standard expand address space : 128-bit address accommodate higher speed networks and mix of data streams

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul TCP/IP Protocol Architecture (cont’d) §Operation of TCP/IP l IP implemented in all end systems and routers l TCP implemented only in the end systems l IP uses globally unique internet addresses for routing and delivery l TCP uses port numbers to uniquely identify applications within a host l TCP segment l IP datagram

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul TCP/IP Protocol Architecture (cont’d) §Internet Standards l organizations IAB (Internet Architecture Board) IETF (Internet Engineering Task Force) IRTF (Internet Research Task Force) working groups

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul OSI Protocol Architecture §OSI RM (Open Systems Interconnection Reference Model) l standardized by ISO l seven layers application, presentation, session, transport,network, data link, physical

By Sanghyun Ahn, Deot. Of Computer Science and Statistics, University of Seoul Internetworking §Terminology l Table 2.1