University of Kansas

Electrical Engineering & Computer Science


EECS 863 Homework 5


Class of Service Queueing for the Internet

The purpose of this homework is to study the use of priority queueing to provide Class-of-Service in the Internet. It is expected that you will report the quality of your performance estimates. To simplify your top level system model it is expected that you will use the hierarchical modeling capability in Extend and include documentation of your blocks in Extend. Submit a print out of your top level model. Submit (send me) your .mox file.

A router output port operates at C Mb/s and supports three traffic types:

  1. 20 pts Assume all three traffic classes are statistically multiplexed in one buffered onto one link. Is the link overloaded for link speeds of C= 5 Mb/s, 35 Mb/s, 50Mb/s, and 600 Mb/s.
  2. 20 pts Assume all three traffic classes are statistically multiplexed onto one link. For link speeds of C= 5 Mb/s, 35 Mb/s, 50Mb/s, and 600 Mb/s use simulation to estimate the average end-to-end delay. Comment on the validity of the results for the overloaded cases. The delay measurements should be taken from the source to the destination and they should be reported for all packets and by priority class.
  3. 20 pts Repeat the simulation in part 1) assuming non-preemptive priority service, with the priority order (CBR) highest priority, (VBR) next level of priority and Best-effort having the lowest priority.
  4. 20 pts Discuss the impact of priority service on the average delay as the capacity increases.

Author

Victor S. Frost, frost@eecs.ku.edu