LEVERAGE
LEarn from Video Extensive Real Atm Gigabit Experiment

Report on Experiments Using Native ATM Services: Deliverable DWP462

A zipped version of this document can be downloaded here.

Abstract :
This deliverable reports on experiments using native ATM programming interfaces for the development of multimedia distributed applications inside the LEVERAGE project. The use of native ATM protocol stacks was found to have some a priori advantages over the TCP/IP based applications currently in use. To assess its usability for real applications, some initiatives were started to evaluate the current status of native ATM implementations, and to get some performance figures about them.

The evaluation of native ATM stacks has been based on two applications specially developed or adapted for this purpose. The first one, WS2NetTest, is a network performance testing application designed to test and compare performance over native ATM and TCP/IP. The second was the LEVERAGE videoconferencing application, which was adapted to work over native ATM in a point to point configuration. Both applications run over Windows 95 PCs; no tests have been carried out on UNIX platforms.

The approach followed in the evaluation of native ATM stacks has consisted in the comparison of behaviour and performance of dual stack applications able to run over native ATM and TCP/IP. This comparison has been made from the point of view of applications, trying to isolate the differences between both stacks and focusing on what happens from the end to end point of view.

The results presented in this deliverable are of two types. First, we try to summarise the experience of using native ATM stacks to develop applications, focusing on aspects like installation, stability, etc. Second, we present some comparative figures that try to show the main performance differences between both alternatives.

Authors: David Fernández (DIT-UPM), Tapio Hiltunen (VTT)
Date: 28/02/98

Contents:

  1. INTRODUCTION
  2. RATIONALE
  3. OBJECTIVES
  4. NATIVE ATM VS. CLASSICAL IP
  5. DESCRIPTION OF TEST ENVIRONMENT
      5.1 WS2NetTest Scenario
      5.2 Videoconference Scenario
  6. WS2NETTEST APPLICATION
  7. EXPERIMENT RESULTS
      7.1 WS2NetTest Tests
        7.1.1 Test 1 - A 2 Mbps flow with varying packets sizes
        7.1.2 Test 2 - A flow of fixed size packet at different speeds
        7.1.3 Test 3 - Roundtrip delay with low load
        7.1.4 Test 4 - Packet Loss for a 2 Mbps ATM circuit
      7.2 Videoconference Tests
        7.2.1 Test objectives and procedure
        7.2.2 Results
          7.2.2.1 UDP test sessions
          7.2.2.2 AAL5 test sessions
          7.2.2.3 CPU usage
          7.2.2.4 Effect of external load in workstation
  8. CONCLUSIONS AND RECOMMENDATIONS
  9. REFERENCES
    APPENDIX I: NATIVE ATM TESTS WITH ATMSOCK INTERFACE

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Last updated 19th August 1998
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