Use of Overbooking in

1

• Use of Overbooking in
• Diffserv-aware MPLS Traffic Engineering
• ltdraft-wlai-tewg-overbook-00.txtgt
• IETF57 TEWG Meeting
• Vienna, July 14, 2003
• Jerry Ash, Wai Sum Lai
• ATT Labs

2

• Overbooking in DS-TE
• Per-domain per-CT overbooking
• Specified in current PROTO, MAM, and RDM drafts
• Based on existing techniques for aggregate TE
• Link size overbooking
• LSP size overbooking
• Per-link per-CT overbooking
• Addressed by this draft
• Two methods compared
• Components-based approach (based on the LOM)
• Integrated approach

3

• Components-Based Approach (the LOM Method)
• New concepts
• LOM local overbooking multiplier
• Normalized bandwidth reserved bandwidth / LOM
• Bandwidth Constraints
• Unaffected by LOM
• Unreserved Bandwidth
• Needs to be adjusted to account for LOM
• Maximum Reservable Bandwidth
• Relationship with LOM currently unspecified
• Impact on operations
• Different formulas for different overbooking
  scenarios

4

• Integrated Approach
• Single concept, single formula
• Maximum reservable bandwidth maximum link
  bandwidth
• OB overbooking factor
• OB LSOM LSPOM LOM
• LSOM link size overbooking multiplier
• LSPOM LSP size overbooking multiplier
• LOM local overbooking multiplier
• Impact on router operations
• Reserved bandwidth Tspec / OB

5

• Integrated Approach
• Issues under discussion
• router interpretation of Tspec to determine
  reserved bandwidth
• relationship to current overbooking models
• validity of Maximum reservable bandwidth
  maximum link bandwidth