HTTP Model for OPNET Mid Semester Presentation

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HTTP Model for OPNET Mid Semester Presentation

• Alon Catz 304565773
• Dina Mesamed 312648074
• Guided by Nir Arad

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Goals

• Learn and understand the HTTP protocol.
• Learn the OPNET environment.
• Expand the existing OPNET model for http traffic
  and make it more similar to the real thing.

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HTTP Protocol Overview

• HTTP is the most used protocol over the internet.
• HTTP works over TCP.
• The most common use of HTTP is retrieval of HTML
  pages.
• HTML pages have inline objects which should
  also be retrieved via http
• There are also others, more advanced, uses of the
  protocol.

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HTTP Protocol Overview

• HTTP Client
• Accepts a request from an application layer.
• Establishes a tcp connection to the host.
• Sends an http request for resource retrieval.
• Waits for an http response on the same tcp
  connection.
• Returns the response for the application layer.

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HTTP Protocol Overview

• HTTP Server
• Listens on a known tcp port (usually 80) for
  client connections.
• Establishes a connection with a client.
• Accepts an http request and processes it.
• Sends an http response.

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Disadvantages of the existing model

• The existing model only simulates the load on the
  server and the size of the response.
• It doesnt simulate the http traffic between the
  server and the client.

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Our goal

• We are going to extend the existing model by
  making the server return an actual response to
  the client.
• This extension will make the simulation much more
  accurate, since the load on the network will also
  be taken into account.

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OPNET model for HTTP

• OPNET has a quite complicated model for
  simulating http.
• OPNET http client
• Accepts most of the parameters concerning the
  request from layers above.
• Those parameters include the size of the response
  and the number of inline objects.
• Generates and sends the first page request.
• Generates and sends inline objects requests
  simultaneously.
• Dies.

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OPNET model for HTTP

• OPNET http server.
• OPNET has a single server model for all kinds of
  applications including http, email, video etc
• This is possible because it doesnt really serve
  anybody.
• It calculates the processing time based on the
  type of the application and the size of the
  response.
• The resulting job incorporates in the server
  load.
• When the job is done, a response packet is sent
  to the client.

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Where we fit in

• Client side
• The size of the response will no longer be
  needed.
• We might need to adjust the client to read the
  additional data.
• The client will parse the response and retrieve
  its inline objects.
• Server side
• We will allow the current model to do all the
  work it does now.
• In addition we will insert code in the response
  generator which will populate the response with
  actual data.
• Response structure
• We will use XML rather then HTML as the response
  data for easier parsing.

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Work to be done

• Write the actual code.
• Make it work.
• Write the final report.
• We estimate the work as about 8 weeks.