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Chapter 7
<ul><li>Processes running in different hosts communicate with an  application-layer protocol   </li></ul><ul><li>Popular a...
<ul><li>Programs could refer to hosts, mailboxes and other resources by their network IP.  </li></ul><ul><ul><li>These Num...
<ul><li>DNS Name Space </li></ul><ul><ul><li>For managing large and changing set of names, need a postal like management, ...
<ul><li>no server has all name-to-IP address mappings </li></ul><ul><li>local name servers: </li></ul><ul><ul><li>each ISP...
<ul><li>Example:  </li></ul><ul><li>host  surf.eurecom.fr  wants IP address of  gaia.cs.umass.edu </li></ul><ul><li>1.  co...
<ul><li>Once (any) name server learns mapping, it  caches  mapping </li></ul><ul><ul><li>cache entries timeout (disappear)...
<ul><li>Three major components :  </li></ul><ul><ul><li>user agents  </li></ul></ul><ul><ul><li>mail servers  </li></ul></...
<ul><li>Mail Servers   </li></ul><ul><ul><li>mailbox  contains incoming messages for user </li></ul></ul><ul><ul><li>messa...
<ul><li>Message Format:  </li></ul><ul><ul><li>SMTP: protocol for exchanging email msgs </li></ul></ul><ul><ul><li>RFC 822...
<ul><li>MIME: Multipurpose Internet Mail Extension   </li></ul><ul><ul><li>For  multimedia mail extension </li></ul></ul><...
<ul><li>SMTP: delivery/storage to receiver’s server </li></ul><ul><li>Mail access protocol: retrieval from server </li></u...
<ul><li>POP3 </li></ul><ul><ul><li>Previous example uses “download and delete” mode.  </li></ul></ul><ul><ul><ul><li>“ Dow...
<ul><li>transfer file to/from remote host </li></ul><ul><li>client/server model </li></ul><ul><ul><li>client:  side that i...
<ul><li>In 1989, CERN:  European Center of Nebular Research , By Berners-Lee.  </li></ul><ul><li>Accessing linked document...
<ul><li>The DNS Name Space </li></ul><ul><li>Resource Records </li></ul><ul><li>Name Servers </li></ul>
<ul><li>A portion of the Internet domain name space. </li></ul>
<ul><li>The principal DNS resource records types. </li></ul>
<ul><li>A portion of a possible DNS database for  cs.vu.nl. </li></ul>
<ul><li>Part of the DNS name space showing the division into zones. </li></ul>
<ul><li>How a resolver looks up a remote name in eight steps. </li></ul>
<ul><li>Architecture and Services </li></ul><ul><li>The User Agent </li></ul><ul><li>Message Formats </li></ul><ul><li>Mes...
<ul><li>Some smileys.  </li></ul>
<ul><li>Basic functions </li></ul><ul><li>Composition </li></ul><ul><li>Transfer </li></ul><ul><li>Reporting </li></ul><ul...
<ul><li>Envelopes and messages.  (a)  Paper mail.  (b)  Electronic mail. </li></ul>
<ul><li>An example display of the contents of a mailbox. </li></ul>
<ul><li>RFC 822 header fields related to message transport. </li></ul>
<ul><li>Some fields used in the RFC 822 message header. </li></ul>
<ul><li>Problems with international languages: </li></ul><ul><li>Languages with accents  (French, German). </li></ul><ul><...
<ul><li>RFC 822 headers added by MIME. </li></ul>
<ul><li>The MIME types and subtypes defined in RFC 2045. </li></ul>
<ul><li>A multipart message containing enriched and audio alternatives. </li></ul>
<ul><li>Transferring a message from  [email_address]  to  carolyn@xyz.com. </li></ul>
(a)  Sending and reading mail when the receiver has a permanent Internet connection and the user agent runs on the same ma...
<ul><li>Using POP3 to fetch three messages . </li></ul>
<ul><li>A comparison of POP3 and IMAP. </li></ul>
<ul><li>Architectural Overview </li></ul><ul><li>Static Web Documents </li></ul><ul><li>Dynamic Web Documents </li></ul><u...
<ul><li>(a)  A Web page  (b)  The page reached by clicking on  Department of Animal Psychology . </li></ul>
<ul><li>The parts of the Web model. </li></ul>
<ul><li>(a)  A browser plug-in.  (b)  A helper application. </li></ul>
<ul><li>A multithreaded Web server with a front end and processing modules. </li></ul>
<ul><li>A server farm. </li></ul>
<ul><li>(a)  Normal request-reply message sequence. </li></ul><ul><li>(b)  Sequence when TCP handoff is used. </li></ul>
<ul><li>Some common URLs. </li></ul>
<ul><li>Some examples of cookies. </li></ul>
<ul><li>(a)  The HTML for a sample Web page.  (b)  The formatted page. </li></ul>(b)
<ul><li>A selection of common HTML tags.  some can have additional parameters. </li></ul>
<ul><li>(a)  An HTML table.  </li></ul><ul><li>(b)  A possible rendition of this table. </li></ul>
<ul><li>(a) The HTML for an  order form. </li></ul><ul><li>(b) The formatted page. </li></ul>(b)
<ul><li>A possible response from the browser to the server with information filled in by the user. </li></ul>
<ul><li>A simple Web page in XML. </li></ul>
<ul><li>A style sheet in XSL. </li></ul>
<ul><li>Steps in processing the information from an HTML form. </li></ul>
<ul><li>A sample HTML page with embedded PHP. </li></ul>
(a)  A Web page containing a form.  (b)  A PHP script for handling the output of the form.  (c)  Output from the PHP scrip...
<ul><li>Use of JavaScript for processing a form. </li></ul>
<ul><li>(a)  Server-side scripting with PHP. </li></ul><ul><li>(b)  Client-side scripting with JavaScript. </li></ul>
<ul><li>A JavaScript program for computing and printing factorials. </li></ul>
<ul><li>An interactive Web page that responds to mouse movement. </li></ul>
<ul><li>The various ways to generate and display content. </li></ul>
<ul><li>The built-in HTTP request methods. </li></ul>
<ul><li>The status code response groups. </li></ul>
<ul><li>Some HTTP message headers. </li></ul>
<ul><li>The start of the output of  www.ietf.org/rfc.html . </li></ul>
<ul><li>Hierarchical caching with three proxies. </li></ul>
<ul><li>(a)  Original Web page.  (b)   Same page after transformation. </li></ul>
<ul><li>Steps in looking up a URL when a CDN is used. </li></ul>
<ul><li>The WAP protocol stack. </li></ul>
<ul><li>The WAP architecture. </li></ul>
<ul><li>Structure of the i-mode data network showing the transport protocols. </li></ul>
<ul><li>Structure of the i-mode software. </li></ul>
<ul><li>Lewis Carroll meets a 16 x 16 screen. </li></ul>
<ul><li>An example of cHTML file. </li></ul>
<ul><li>A comparison of first-generation WAP and i-mode. </li></ul>
<ul><li>New features of WAP 2.0. </li></ul><ul><li>Push model as well as pull model. </li></ul><ul><li>Support for integra...
<ul><li>WAP 2.0 supports two protocol stacks. </li></ul>
<ul><li>The XHTML Basic modules and tags. </li></ul>
<ul><li>Introduction to Audio </li></ul><ul><li>Audio Compression </li></ul><ul><li>Streaming Audio </li></ul><ul><li>Inte...
<ul><li>(a)  A sine wave.  (b)  Sampling the sine wave.  (c)  Quantizing the samples to 4 bits. </li></ul>
<ul><li>(a)  The threshold of audibility as a function of frequency. </li></ul><ul><li>(b)  The masking effect. </li></ul>
<ul><li>A straightforward way to implement clickable music on a Web page. </li></ul>
When packets carry alternate samples, the loss of a packet reduces the temporal resolution rather than creating a gap in t...
<ul><li>The media player buffers input from the media server and plays from the buffer rather than directly from the netwo...
<ul><li>RTSP commands from the player to the server. </li></ul>
<ul><li>A student radio station. </li></ul>
<ul><li>The H323 architectural model for Internet telephony. </li></ul>
<ul><li>The H323 protocol stack. </li></ul>
<ul><li>Logical channels between the caller and callee during a call. </li></ul>
<ul><li>The SIP methods defined in the core specification. </li></ul>
<ul><li>Use a proxy and redirection servers with SIP. </li></ul>
 
<ul><li>The scanning pattern used for NTSC video and television. </li></ul>
<ul><li>The operation of JPEG in lossy sequential mode. </li></ul>
<ul><li>(a)  RGB input data. </li></ul><ul><li>(b)  After block preparation. </li></ul>
<ul><li>(a)  One block of the  Y  matrix. </li></ul><ul><li>(b)  The DTC coefficients. </li></ul>(a) (b)
<ul><li>Computation of the quantized DTC coefficients. </li></ul>
<ul><li>The order in which the quantized values are transmitted. </li></ul>
<ul><li>Synchronization of the audio and video streams in MPEG-1. </li></ul>
<ul><li>Three consecutive frames. </li></ul>
<ul><li>Overview of a video-on-demand system. </li></ul>
<ul><li>A video server storage hierarchy. </li></ul>
<ul><li>The hardware architecture of a typical video server. </li></ul>
<ul><li>MBone consists of multicast islands connected by tunnels. </li></ul>
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Jaimin chp-7 - application layer- 2011 batch

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GTU-MCA-SEM IV - Fundamentals of Networking

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Transcript of "Jaimin chp-7 - application layer- 2011 batch"

  1. 1. Chapter 7
  2. 2. <ul><li>Processes running in different hosts communicate with an application-layer protocol </li></ul><ul><li>Popular application-level protocols: </li></ul><ul><ul><li>DNS </li></ul></ul><ul><ul><li>HTTP </li></ul></ul><ul><ul><li>FTP </li></ul></ul><ul><ul><li>SMTP / POP3 / IMAP </li></ul></ul><ul><li>Programming network applications </li></ul><ul><ul><li>socket API </li></ul></ul>
  3. 3. <ul><li>Programs could refer to hosts, mailboxes and other resources by their network IP. </li></ul><ul><ul><li>These Numbers are difficult to remember by people? </li></ul></ul><ul><ul><li>Also, if moving the servers to different machine? </li></ul></ul><ul><ul><li>Use names instead of IP numbers. </li></ul></ul><ul><ul><ul><li>Ex. ce.sharif.edu, veisi@yahoo.com </li></ul></ul></ul><ul><ul><li>Need a mechanism to convert names to IP Number </li></ul></ul><ul><li>Use a file: hosts.txt </li></ul><ul><li>As the number of PCs increase? </li></ul><ul><ul><li>Size increase, Conflict of host names </li></ul></ul><ul><li>Need a central manager: </li></ul><ul><ul><li>DNS: Domain Name System </li></ul></ul>
  4. 4. <ul><li>DNS Name Space </li></ul><ul><ul><li>For managing large and changing set of names, need a postal like management, </li></ul></ul><ul><ul><ul><li>Ex. No. 4, Azadi St., Tehran, Iran </li></ul></ul></ul><ul><ul><li>Hierarchical addressing </li></ul></ul><ul><li>Top-level domain: </li></ul><ul><ul><li>200 top-level domains </li></ul></ul>
  5. 5. <ul><li>no server has all name-to-IP address mappings </li></ul><ul><li>local name servers: </li></ul><ul><ul><li>each ISP, company has local (default) name server </li></ul></ul><ul><ul><li>host DNS query first goes to local name server </li></ul></ul><ul><li>authoritative name server: </li></ul><ul><ul><li>for a host: stores that host’s IP address, name </li></ul></ul><ul><ul><li>can perform name/address translation for that host’s name </li></ul></ul><ul><li>Why not centralize DNS? </li></ul><ul><li>single point of failure </li></ul><ul><li>traffic volume </li></ul><ul><li>distant centralized database </li></ul><ul><li>maintenance </li></ul>
  6. 6. <ul><li>Example: </li></ul><ul><li>host surf.eurecom.fr wants IP address of gaia.cs.umass.edu </li></ul><ul><li>1. contacts its local DNS server, dns.eurecom.fr </li></ul><ul><li>2. dns.eurecom.fr contacts root name server, if necessary </li></ul><ul><li>3. root name server contacts authoritative name server, dns.umass.edu, if necessary </li></ul>requesting host surf.eurecom.fr gaia.cs.umass.edu root name server authoritative name server dns.umass.edu 1 2 3 4 5 6 local name server dns.eurecom.fr
  7. 7. <ul><li>Once (any) name server learns mapping, it caches mapping </li></ul><ul><ul><li>cache entries timeout (disappear) after some time </li></ul></ul><ul><li>DNS Records </li></ul><ul><ul><li>format: (name, TTL, value, type) </li></ul></ul><ul><ul><li>Records types: </li></ul></ul>
  8. 8. <ul><li>Three major components : </li></ul><ul><ul><li>user agents </li></ul></ul><ul><ul><li>mail servers </li></ul></ul><ul><ul><li>simple mail transfer protocol: SMTP </li></ul></ul><ul><li>User Agent </li></ul><ul><ul><li>Sometimes is called: </li></ul></ul><ul><ul><li>“ mail reader” </li></ul></ul><ul><ul><li>composing, editing, reading mail messages </li></ul></ul><ul><ul><li>e.g., Eudora, Outlook, elm, Netscape Messenger </li></ul></ul><ul><ul><li>outgoing, incoming messages stored on server </li></ul></ul>user mailbox outgoing message queue mail server user agent user agent user agent mail server user agent user agent mail server user agent SMTP SMTP SMTP
  9. 9. <ul><li>Mail Servers </li></ul><ul><ul><li>mailbox contains incoming messages for user </li></ul></ul><ul><ul><li>message queue of outgoing (to be sent) mail messages </li></ul></ul><ul><ul><li>SMTP protocol between mail servers to send email messages </li></ul></ul><ul><ul><ul><li>“ client”: sending mail server (sending agent) </li></ul></ul></ul><ul><ul><ul><li>“ server”: receiving mail server (receiving agent) </li></ul></ul></ul>mail server user agent user agent user agent mail server user agent user agent mail server user agent SMTP SMTP SMTP
  10. 10. <ul><li>Message Format: </li></ul><ul><ul><li>SMTP: protocol for exchanging email msgs </li></ul></ul><ul><ul><li>RFC 822: standard for text message format: </li></ul></ul><ul><ul><li>header lines, e.g., </li></ul></ul><ul><ul><ul><li>To: </li></ul></ul></ul><ul><ul><ul><li>From: </li></ul></ul></ul><ul><ul><ul><li>Subject: </li></ul></ul></ul><ul><ul><ul><li>different from SMTP commands ! </li></ul></ul></ul><ul><ul><li>body </li></ul></ul><ul><ul><ul><li>the “message”, ASCII characters only </li></ul></ul></ul>header body blank line
  11. 11. <ul><li>MIME: Multipurpose Internet Mail Extension </li></ul><ul><ul><li>For multimedia mail extension </li></ul></ul><ul><li>Text </li></ul><ul><ul><li>example subtypes: plain, html </li></ul></ul><ul><li>Image </li></ul><ul><ul><li>example subtypes: jpeg, gif </li></ul></ul><ul><li>Audio </li></ul><ul><ul><li>example subtypes: basic (8-bit mu-law encoded), 32kadpcm (32 kbps coding) </li></ul></ul><ul><li>Video </li></ul><ul><ul><li>example subtypes: mpeg, quicktime </li></ul></ul><ul><li>Application </li></ul><ul><ul><li>other data that must be processed by reader before “viewable” </li></ul></ul><ul><ul><li>example subtypes: msword, octet-stream </li></ul></ul>
  12. 12. <ul><li>SMTP: delivery/storage to receiver’s server </li></ul><ul><li>Mail access protocol: retrieval from server </li></ul><ul><ul><li>POP: Post Office Protocol [RFC 1939] </li></ul></ul><ul><ul><ul><li>authorization (agent <-->server) and download </li></ul></ul></ul><ul><ul><li>IMAP: Internet Mail Access Protocol [RFC 1730] </li></ul></ul><ul><ul><ul><li>more features (more complex) </li></ul></ul></ul><ul><ul><ul><li>manipulation of stored msgs on server </li></ul></ul></ul><ul><ul><li>HTTP: Hotmail , Yahoo! Mail, etc. </li></ul></ul>SMTP access protocol receiver’s mail server user agent sender’s mail server user agent SMTP
  13. 13. <ul><li>POP3 </li></ul><ul><ul><li>Previous example uses “download and delete” mode. </li></ul></ul><ul><ul><ul><li>“ Download” brings the mail into client computer. </li></ul></ul></ul><ul><ul><ul><li>“ Delete” removes the mail from the mail server. Mr.X cannot re-read e-mail if he changes client computer. </li></ul></ul></ul><ul><ul><li>“ Download-and-keep”: leaves the message on the mail server. </li></ul></ul><ul><ul><li>POP3 is stateless across sessions. </li></ul></ul><ul><li>IMAP </li></ul><ul><ul><li>Keep all messages in one place: the server </li></ul></ul><ul><ul><li>Allows user to organize messages in folders </li></ul></ul><ul><ul><li>IMAP keeps user state across sessions: </li></ul></ul><ul><ul><ul><li>names of folders and mappings between message IDs and folder name </li></ul></ul></ul>
  14. 14. <ul><li>transfer file to/from remote host </li></ul><ul><li>client/server model </li></ul><ul><ul><li>client: side that initiates transfer (either to/from remote) </li></ul></ul><ul><ul><li>server: remote host </li></ul></ul><ul><li>ftp: RFC 959 </li></ul><ul><li>ftp server: port 21 </li></ul>file transfer local file system remote file system user at host FTP server FTP user interface FTP client
  15. 15. <ul><li>In 1989, CERN: European Center of Nebular Research , By Berners-Lee. </li></ul><ul><li>Accessing linked documents, support Text, Image, Audio, Video, … </li></ul><ul><li>People think that this is “Internet” ! </li></ul><ul><li>Hypertext Browsers: </li></ul><ul><ul><li>Mosaic, Netscape, IE, … </li></ul></ul><ul><li>Use HTML (Hyper-Text Markup Language) as a common language of web. </li></ul>
  16. 16. <ul><li>The DNS Name Space </li></ul><ul><li>Resource Records </li></ul><ul><li>Name Servers </li></ul>
  17. 17. <ul><li>A portion of the Internet domain name space. </li></ul>
  18. 18. <ul><li>The principal DNS resource records types. </li></ul>
  19. 19. <ul><li>A portion of a possible DNS database for cs.vu.nl. </li></ul>
  20. 20. <ul><li>Part of the DNS name space showing the division into zones. </li></ul>
  21. 21. <ul><li>How a resolver looks up a remote name in eight steps. </li></ul>
  22. 22. <ul><li>Architecture and Services </li></ul><ul><li>The User Agent </li></ul><ul><li>Message Formats </li></ul><ul><li>Message Transfer </li></ul><ul><li>Final Delivery </li></ul>
  23. 23. <ul><li>Some smileys. </li></ul>
  24. 24. <ul><li>Basic functions </li></ul><ul><li>Composition </li></ul><ul><li>Transfer </li></ul><ul><li>Reporting </li></ul><ul><li>Displaying </li></ul><ul><li>Disposition </li></ul>
  25. 25. <ul><li>Envelopes and messages. (a) Paper mail. (b) Electronic mail. </li></ul>
  26. 26. <ul><li>An example display of the contents of a mailbox. </li></ul>
  27. 27. <ul><li>RFC 822 header fields related to message transport. </li></ul>
  28. 28. <ul><li>Some fields used in the RFC 822 message header. </li></ul>
  29. 29. <ul><li>Problems with international languages: </li></ul><ul><li>Languages with accents (French, German). </li></ul><ul><li>Languages in non-Latin alphabets (Hebrew, Russian). </li></ul><ul><li>Languages without alphabets (Chinese, Japanese). </li></ul><ul><li>Messages not containing text at all (audio or images). </li></ul>
  30. 30. <ul><li>RFC 822 headers added by MIME. </li></ul>
  31. 31. <ul><li>The MIME types and subtypes defined in RFC 2045. </li></ul>
  32. 32. <ul><li>A multipart message containing enriched and audio alternatives. </li></ul>
  33. 33. <ul><li>Transferring a message from [email_address] to carolyn@xyz.com. </li></ul>
  34. 34. (a) Sending and reading mail when the receiver has a permanent Internet connection and the user agent runs on the same machine as the message transfer agent. (b) Reading e-mail when the receiver has a dial-up connection to an ISP.
  35. 35. <ul><li>Using POP3 to fetch three messages . </li></ul>
  36. 36. <ul><li>A comparison of POP3 and IMAP. </li></ul>
  37. 37. <ul><li>Architectural Overview </li></ul><ul><li>Static Web Documents </li></ul><ul><li>Dynamic Web Documents </li></ul><ul><li>HTTP – The HyperText Transfer Protocol </li></ul><ul><li>Performance Ehnancements </li></ul><ul><li>The Wireless Web </li></ul>
  38. 38. <ul><li>(a) A Web page (b) The page reached by clicking on Department of Animal Psychology . </li></ul>
  39. 39. <ul><li>The parts of the Web model. </li></ul>
  40. 40. <ul><li>(a) A browser plug-in. (b) A helper application. </li></ul>
  41. 41. <ul><li>A multithreaded Web server with a front end and processing modules. </li></ul>
  42. 42. <ul><li>A server farm. </li></ul>
  43. 43. <ul><li>(a) Normal request-reply message sequence. </li></ul><ul><li>(b) Sequence when TCP handoff is used. </li></ul>
  44. 44. <ul><li>Some common URLs. </li></ul>
  45. 45. <ul><li>Some examples of cookies. </li></ul>
  46. 46. <ul><li>(a) The HTML for a sample Web page. (b) The formatted page. </li></ul>(b)
  47. 47. <ul><li>A selection of common HTML tags. some can have additional parameters. </li></ul>
  48. 48. <ul><li>(a) An HTML table. </li></ul><ul><li>(b) A possible rendition of this table. </li></ul>
  49. 49. <ul><li>(a) The HTML for an order form. </li></ul><ul><li>(b) The formatted page. </li></ul>(b)
  50. 50. <ul><li>A possible response from the browser to the server with information filled in by the user. </li></ul>
  51. 51. <ul><li>A simple Web page in XML. </li></ul>
  52. 52. <ul><li>A style sheet in XSL. </li></ul>
  53. 53. <ul><li>Steps in processing the information from an HTML form. </li></ul>
  54. 54. <ul><li>A sample HTML page with embedded PHP. </li></ul>
  55. 55. (a) A Web page containing a form. (b) A PHP script for handling the output of the form. (c) Output from the PHP script when the inputs are &quot;Barbara&quot; and 24 respectively.
  56. 56. <ul><li>Use of JavaScript for processing a form. </li></ul>
  57. 57. <ul><li>(a) Server-side scripting with PHP. </li></ul><ul><li>(b) Client-side scripting with JavaScript. </li></ul>
  58. 58. <ul><li>A JavaScript program for computing and printing factorials. </li></ul>
  59. 59. <ul><li>An interactive Web page that responds to mouse movement. </li></ul>
  60. 60. <ul><li>The various ways to generate and display content. </li></ul>
  61. 61. <ul><li>The built-in HTTP request methods. </li></ul>
  62. 62. <ul><li>The status code response groups. </li></ul>
  63. 63. <ul><li>Some HTTP message headers. </li></ul>
  64. 64. <ul><li>The start of the output of www.ietf.org/rfc.html . </li></ul>
  65. 65. <ul><li>Hierarchical caching with three proxies. </li></ul>
  66. 66. <ul><li>(a) Original Web page. (b) Same page after transformation. </li></ul>
  67. 67. <ul><li>Steps in looking up a URL when a CDN is used. </li></ul>
  68. 68. <ul><li>The WAP protocol stack. </li></ul>
  69. 69. <ul><li>The WAP architecture. </li></ul>
  70. 70. <ul><li>Structure of the i-mode data network showing the transport protocols. </li></ul>
  71. 71. <ul><li>Structure of the i-mode software. </li></ul>
  72. 72. <ul><li>Lewis Carroll meets a 16 x 16 screen. </li></ul>
  73. 73. <ul><li>An example of cHTML file. </li></ul>
  74. 74. <ul><li>A comparison of first-generation WAP and i-mode. </li></ul>
  75. 75. <ul><li>New features of WAP 2.0. </li></ul><ul><li>Push model as well as pull model. </li></ul><ul><li>Support for integrating telephony into apps. </li></ul><ul><li>Multimedia messaging. </li></ul><ul><li>Inclusion of 264 pictograms. </li></ul><ul><li>Interface to a storage device. </li></ul><ul><li>Support for plug-ins in the browser. </li></ul>
  76. 76. <ul><li>WAP 2.0 supports two protocol stacks. </li></ul>
  77. 77. <ul><li>The XHTML Basic modules and tags. </li></ul>
  78. 78. <ul><li>Introduction to Audio </li></ul><ul><li>Audio Compression </li></ul><ul><li>Streaming Audio </li></ul><ul><li>Internet Radio </li></ul><ul><li>Voice over IP </li></ul><ul><li>Introduction to Video </li></ul><ul><li>Video Compression </li></ul><ul><li>Video on Demand </li></ul><ul><li>The MBone – The Multicast Backbone </li></ul>
  79. 79. <ul><li>(a) A sine wave. (b) Sampling the sine wave. (c) Quantizing the samples to 4 bits. </li></ul>
  80. 80. <ul><li>(a) The threshold of audibility as a function of frequency. </li></ul><ul><li>(b) The masking effect. </li></ul>
  81. 81. <ul><li>A straightforward way to implement clickable music on a Web page. </li></ul>
  82. 82. When packets carry alternate samples, the loss of a packet reduces the temporal resolution rather than creating a gap in time.
  83. 83. <ul><li>The media player buffers input from the media server and plays from the buffer rather than directly from the network. </li></ul>
  84. 84. <ul><li>RTSP commands from the player to the server. </li></ul>
  85. 85. <ul><li>A student radio station. </li></ul>
  86. 86. <ul><li>The H323 architectural model for Internet telephony. </li></ul>
  87. 87. <ul><li>The H323 protocol stack. </li></ul>
  88. 88. <ul><li>Logical channels between the caller and callee during a call. </li></ul>
  89. 89. <ul><li>The SIP methods defined in the core specification. </li></ul>
  90. 90. <ul><li>Use a proxy and redirection servers with SIP. </li></ul>
  91. 92. <ul><li>The scanning pattern used for NTSC video and television. </li></ul>
  92. 93. <ul><li>The operation of JPEG in lossy sequential mode. </li></ul>
  93. 94. <ul><li>(a) RGB input data. </li></ul><ul><li>(b) After block preparation. </li></ul>
  94. 95. <ul><li>(a) One block of the Y matrix. </li></ul><ul><li>(b) The DTC coefficients. </li></ul>(a) (b)
  95. 96. <ul><li>Computation of the quantized DTC coefficients. </li></ul>
  96. 97. <ul><li>The order in which the quantized values are transmitted. </li></ul>
  97. 98. <ul><li>Synchronization of the audio and video streams in MPEG-1. </li></ul>
  98. 99. <ul><li>Three consecutive frames. </li></ul>
  99. 100. <ul><li>Overview of a video-on-demand system. </li></ul>
  100. 101. <ul><li>A video server storage hierarchy. </li></ul>
  101. 102. <ul><li>The hardware architecture of a typical video server. </li></ul>
  102. 103. <ul><li>MBone consists of multicast islands connected by tunnels. </li></ul>

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