MODULE and Messaging 1

Messages exchanged among Internet subscribers Vary from a simple text based messages to one that carries different attachments –Word, PowerPoint documents –Any computer file –Video and audio clippings etc.

Messaging expanded to include a number of other functions and services Document sharing and collaboration Whiteboard applications Scheduling of group activities Etc.

Collaboration and Sharing Internet User 1 User 2 Document for Sharing or Collaboration Sharing: Both users can see the document but only one can make changes Collaboration: Both users can see and also make changes to the document NetMeeting

Implementation Of Messaging Server Client 1 Client 2 Lotus Domino server, Microsoft Exchange Server Internet Internet service Provider WWW Services

Major Messaging Products Microsoft Exchange Server –Outlook and Outlook Express Clients Lotus Domino Server –cc:Mail –Lotus Notes (Client) Netscape ???

MODULE Voice Over IP and Internet Telephony 7

Voice Over IP and Internet Telephony Defined The use of the internet to transmit voice in real-time –Transmission of digitized voice using the Internet Protocol Internet Telephony is an example –Usage of the Internet to transmit telephone calls

Internet Telephony Defined Using the Internet (TCP/IP) for largely the telephone related applications –Termination of voice traffic

Voice over IP Prospects and Challenges Voice transmission over the Internet has been identified as one of the largest growth areas –Companies will in the future use the Internet extensively for voice communications Current IP is not well suited for voice transmission –Latency being the biggest drawback Bandwidth restrictions also hamper voice transmission IP is being improved to carry voice

Internet Telephony A growing market Further information – Current Products (???) –Net meeting (Microsoft) –ICQ –Cooltalk (Netscape) etc. Long-term focus is on regularly using the Internet as a viable alternative to the Plain Old Telephone Service (POTS) H.323 is the prominent standard for Internet telephony

Sample Telephony Applications Computer-to-Computer Calling Computer-to-Phone Calling: –Requires ITSP service in addition to regular ISP serviceITSP service – Phone-to-phone –Using TCP/IP Live Motion Video –Video Conferencing Whiteboarding: –Share and edit photos, documents and drawings with others in real time. Voice Mail: –Record compressed voice files and sending them as attachments.

MODULE Virtual Private Networks (VPN) 13

VPN Defined A private network that uses the public network infrastructure A secured web of tunnels that links various nodes to form the Virtual Private Network

Virtual Private Network Public VPN

VPN Implementation Internet Company’s Intranet Point-to-Point Tunneling Protocol (PPTP) Fire Wall

VPN Past and Present Past –Based on PSTN (Public Switched Telephone Network) Present –Based on next generation public network technologies Source: VPNWorx, VPN Quick Reference GuideVPNWorx, VPN Quick Reference Guide

Base Technologies for VPN Carrier IP PPTP Frame Relay ATM

Areas of Applications All major business organizations that require a secured Extranet

MODULE WAN and Access Technologies 20

WAN Scope Enterprise-wide Metropolitan and National Global Underlying network infrastructure for the Internet Fastest growing network –Growth is appreciable in the area of Virtual Private Network

The Early Days of Communications and Computing Telecommunication –Centered on analog technology Data communication needs –Centered around digital technology Digital to analog interface –For long distance communications

Long-distance Communications Digital Modulation Plain Old Telephone Service (POTS) Analog Interface

Initial WANs Introduced to overcome the limitations of general purpose analog telephone lines used –Better conditioned lines such as leased lines were used Driven by a collection of computers for routing the data traffic from source to destination Arpanet was the first WAN to be created X.25 was the initial communication technology used –X.21 was used in Europe

Basic Components of the WAN Leased lines Computers/ Routing algorithms Routing devices X.25 Driven

Present Status of WANs Information is carried in digitized form in many segments of the WAN Digital communication lines –Over copper wire –Over fiber-optics Telecommunications and computer communications are merging in terms of deploying digital technology

WANs: Present and Future Move towards digital technology Technologies –Frame Relay –ATM Point-to-point digital communication will become widely used in the future The WAN of the future will be designed to meet with the increasing bandwidth demands of the Internet –Internet2

ATM operating at several hundred Mbps Internet2: The WAN of the Future Ramp Business Computer System ATM Switches High speed digital lines 28

Possible Convergence Digital Technology Networks –Local –Enterprise –Wide area –Global ATM Point-to-point ATM connection is possible probably under a single technology

ATM Promise Server Client 1 Client 2 25 Mbps ISP 100 Mbps Internet Backbone 1 Gbps 300 Mbps

Challeng Posed by Gigabit Ethernet to ATM 1 Gbps (Gigabit) 100 Mbps (Fast) 10 Mbps 1 Mbps (Past) Ethernet Evolution Client 2 10 Mbps/ 100 Mbps/ 1 Gbps Server ISP Client 1 Hub

Wide Area Network Technologies WAN Technologies: X.25 (old) FDDI Frame Relay ATM Los Angeles Seattle New York Florida

Front-end Access Technologies ISDN xDSL Cable modem Direct satellite access ADSL is an example of xDSL

Access Speeds Fastest speed of an analog modem is around 56K bps Newer technologies operate at faster speeds Newer technologies have made a significant contribution in increasing the speed of communication

Digital Internet Technologies Summarized FDDI Frame Relay ATM Cable Modem Direct Satellite Access xDSL ISDN 35

MODULE Audio and Video Streaming 36

Audio and Video Streaming Deliver continuous audio and video streams over a low bandwidth connection Packet switching networks do no guarantee real-time and continuous delivery of data packets Streaming involves compression and decompression (CODEC)

Application Areas Dissemination of multimedia information on the web Training and education Etc.

Streaming Examples Streaming Software Audio (wav) Video (AVI) Real Format RM, RMA, RT, RP etc. Windows Format ASF etc. 39

Hosting of Streamed Media Streaming Server (Real Server or Windows Media Server) Internet Streaming at 28.8, 56, 128 etc. Kbps 40

Method of Delivery Unicasting Multicasting Broadcasting

Major Streaming Technologies Real Microsoft Windows Media Technologies

MODULE Video Conferencing 43

Video Conferencing The exchanging of audio and video information while engaged in conferencing

Major Types of Video Conferencing Dedicated video conferencing –Telecommunication lines are used solely for the purpose of setting up a video conferencing facility Desktop video conferencing –Video conferencing conducted from a computer connected to the Internet

Video Conferencing Standard H.232 Series of standards

Sample Desktop Video Conferencing Products CU-SeeMee Intel ProShare Microsoft NetMeeting PictureTel

Keywords Intranet, Extranet, Internet VPN, PPTP Real Media and Windows Media Network appliance and Internet Appliance Sharing, Collaboration Messaging Server and Messaging Client

Keywords SMTP, POP3, IMAP VoIP, H.323, IPv6 X.25, ATM, Frame Relay, FDDI T1, T3, OC1, OC2 ISDN, xDSL, Cable Modem, Satellite Unicasting, Multicasting and Broadcasting

Microcomputer-based Distributed Architecture Fiber Optic Backbone (FDDI) Mainframe/ Minicomputer Systems Bus LAN Ring LAN WAN Gateway (TCP/IP) Modem Gateway External Digital/ Analog Lines

Microcomputers Widespread usage –Serious business computer Dramatic increase in power –Comparable to mainframes of the past Declining cost –Affordable to use in all levels of business Communication device –Access services and resources on the Internet

Connectivity Computers are increasingly being viewed as resources in a network and not simply as stand-alone units any more LANs, Departmental networks, Enterprise networks, WANs etc. are deployed widely in business

Downsizing: Path of Evolution Centralized Mainframe Distributed Network Client-Server Architecture Thin-client concept More power to the user Better management of shared dataReduced cost of ownership

Client-Server Computing Architecture Centralized data –Control and management Distributed processing –Processing using client-tools Mainframe advantage Microcomputer flexibility

Preview of Client-Server Computing Back-end data storage and retrieval. Front-end interface and data manipulation tools. Server Clients 55

A Preview of Thin-Client Concept Powerful Server Thin Clients Limited front-end processing and storage Extensive back-end data storage, retrieval and Processing

Digitization Of Telecom Network Mode (ATM)

Front-end Access Technologies ISDN xDSL Cable modem Direct satellite access ADSL is an example of xDSL

Access Speeds Fastest speed of an analog modem is around 56K bps Newer technologies operate at faster speeds –In the Mbps region Newer technologies have made a significant contribution in increasing the speed of communication