1. Speed, Duplex and the Auto-Negotiation Function cs. 522 12/13/2002 M. Erickson

2. Problem Statment  How does the Auto-Negotiation function “generate” duplex a mismatch?  What is the impact?  How can this be resolved?

3. Auto-Negotiation  Relies on an advertisement of a systems capabilities  It doesn’t mean auto detection  Functions through an exchange of a code word

4. Pit falls of Auto- Negotiation  Duplex Mismatch  Poorly designed drivers

5. Understanding a duplex mismatch  Auto-Negotiation Function  CSMA/CD  TCP

6. Results  Duplex Mismatch –Types of errors –Reduction in transmission rates –Direction matters  Other Impacts to Performance –CPU –NIC –OS