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MODULE. Email and Messaging. Email. 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.
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MODULE Email and Messaging
Email • 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 • Email expanded to include a number of other functions and services • Document sharing and collaboration • Whiteboard applications • Scheduling of group activities • Etc.
Collaboration and Sharing User 1 Document for Sharing or Collaboration Sharing: Both users can see the document but only one can make changes Internet Collaboration: Both users can see and also make changes to the document User 2 NetMeeting
WWW Services Client 1 Client 2 Internet Internet service Provider Server Implementation Of Messaging Lotus Domino server, Microsoft Exchange Server
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
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 • http://www.internettelephony.com/ • 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 ApplicationsComputer-to-Computer Calling • Computer-to-Phone Calling: • Requires ITSP service in addition to regular ISP service • www.dialpad.com • 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)
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 Point-to-Point Tunneling Protocol (PPTP) Fire Wall Company’s Intranet
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 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
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
Interface Digital Digital Analog Plain Old Telephone Service (POTS) Long-distance Communications Modulation
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
Routing devices Leased lines Basic Components of the WAN X.25 Driven Computers/ Routing algorithms
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
Internet2: The WAN of the Future ATM Switches ATM operating at several hundred Mbps Ramp High speed digital lines Business Computer System
ATM Possible Convergence Digital Technology • Networks • Local • Enterprise • Wide area • Global Point-to-point ATM connection is possible probably under a single technology
Internet Backbone 1 Gbps Client 1 Client 2 25 Mbps 300 Mbps 100 Mbps Server ISP ATM Promise
1 Gbps (Gigabit) 100 Mbps (Fast) 10 Mbps 1 Mbps (Past) Ethernet Evolution Client 1 Client 2 Hub 10 Mbps/ 100 Mbps/ 1 Gbps ISP Server Challeng Posed by Gigabit Ethernet to ATM
Wide Area Network Technologies WAN Technologies: X.25 (old) FDDI Frame Relay ATM New York Seattle Los Angeles 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 Direct Satellite Access ISDN FDDI Frame Relay ATM xDSL Cable Modem
MODULE Audio and Video Streaming
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 Raw File Streamed File Windows Format ASF etc. Streaming Software Audio (wav) Video (AVI) Real Format RM, RMA, RT, RP etc.
Hosting of Streamed Media Internet Streaming Server (Real Server or Windows Media Server) Streaming at 28.8, 56, 128 etc. Kbps
Method of Delivery • Unicasting • Multicasting • Broadcasting
Major Streaming Technologies • Real • Microsoft Windows Media Technologies
MODULE Video Conferencing
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
Bus LAN External Digital/ Analog Lines Modem Gateway Ring LAN WAN Gateway (TCP/IP) Microcomputer-based Distributed Architecture Mainframe/ Minicomputer Systems Fiber Optic Backbone (FDDI)