Most of the speech compression standards result in a constant bit rate stream (CBR). However, with silence suppresion, the resulting stream in variable bit rate (VBR). We studied the performance of VBR voice over ATM and found that the number of circuits that can be accomodated does not go up very much. This is because of the tight delay requirements of voice traffic. The tighter the delay requirement, less is the number of voice circuits that can be multiplexed on a given trunk. We present our recent reseach results in this area and explain the results.

This talk covers the following topics:

• VBR Voice over ATM: Analysis of Multiplexing Gain and Effect of Scheduling & Drop Policies
• Performance Requirements
• N-Source Configuration
• Simulation configuration
• CDV
• Source Model
• Performance Metrics
• Multiplexing Gain
• Scheduling Policies
• Scheduling Results: 1 Buf/VC
• Scheduling Policies: Results I
• Scheduling Results: 2 Bufs/VC
• Scheduling Policies: Results II
• Scheduling Results: Medium Load
• Scheduling Results: Heavy Load
• Scheduling Policies: Results III
• Drop Policies
• Drop Policies Results
• Drop Polices Results: Heavy Load
• Drop Policies: Results
• Summary
• Future Work
• References

Presentation slides in Adobe Acrobat Format: 1 slide/page