How Traffic Management Impacts Quality of Service

The Traffic Management functions of shaping, scheduling, and policing impact the quality of service, rate limiting, and relative flow priority of important network functions. Correct implementation of these functions has a major impact on the quality of service provided by the network and on the overall traffic engineering within the network. Although execution of traffic management functionality is done by the switching device, appropriate traffic management for the network and the networking applications requires substantial high-level design and proper programming of the switching device.

This white paper, the first of three white papers covering traffic management, focuses on scheduling, provides an overview of the three functions to put the scheduling function in context. It includes discussion on:

  • Scheduling, shaping, and policing
  • Traffic priority queueing at a port
  • Port scheduling algorithms

Designing and implementing a port scheduling solution for a packet switch is difficult. There are many choices that need to be made including the number of queues to use, the scheduling algorithm for each queue, bandwidth limits for each queue, and queue depth/buffering limits for each queue. The choices for these values are usually different depending on whether the port is facing a subscriber or facing the network. Each switching ASIC has a different approach to deal with these items and expertise is needed to avoid (or troubleshoot) some of the issues and problems listed above.

IP Infusion Innovations has experience developing these software solutions and as a development partner with a number of switching industry leaders such as Broadcom and Cavium they have expertise and insight into the implementation of these features in the leading switch ASICs. If you need help or guidance using Ethernet switching in your networking product, IP Infusion can help.