Bandwidth Constraints Models for Diffserv-aware MPLS TE: Performance Evaluation

1. Bandwidth Constraints Models for Diffserv-aware MPLS TE: Performance Evaluation <draft-wlai-tewg-bcmodel-03.txt> IETF’58 TEWG Meeting Minneapolis, November 13, 2003 Wai Sum Lai AT&T Labs wlai@att.com

2. What’s changed • More explanatory text • BC model design considerations • New sections • Improving Class 2 Performance at the Expense of Class 3 • Comparing Bandwidth Constraints of Different Models

3. Operational Characteristics General trade-off • bandwidth sharing to achieve greater efficiency under normal conditions • robust class protection/isolation under overload Russian Dolls Model • higher degree of sharing allowed • leads to its inability to offer robust class isolation under overload conditions Maximum Allocation Model • each class has its own bandwidth access limits • leads to reduced degree of interference among the different classes

4. Performance Comparison Russian Dolls Model • allows greater sharing of bandwidth among different classes • performs somewhat better under normal conditions • works well when preemption is fully enabled • under partial preemption, not all preemption modes work equally well Maximum Allocation Model • does not depend on the use of preemption • is relatively insensitive to the different preemption modes when preemption is used • provides more robust class isolation under overload

5. Next Step As agreed in the last two meetings, to progress as an individual submission, with review by the TEWG