1 / 6

Bandwidth Constraint Models for Diffserv-aware MPLS Traffic Engineering

Bandwidth Constraint Models for Diffserv-aware MPLS Traffic Engineering <draft-wlai-tewg-bcmodel-00.txt> IETF’55 TEWG Meeting Atlanta, Georgia, November 20, 2002 Wai Sum Lai AT&T Labs wlai@att.com. Bandwidth Allocation Algorithms

melindamoreno
Download Presentation

Bandwidth Constraint Models for Diffserv-aware MPLS Traffic Engineering

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Bandwidth Constraint Models for Diffserv-aware MPLS Traffic Engineering <draft-wlai-tewg-bcmodel-00.txt> IETF’55 TEWG Meeting Atlanta, Georgia, November 20, 2002 Wai Sum Lai AT&T Labs wlai@att.com

  2. Bandwidth Allocation Algorithms To determine if bandwidth should be granted to a new LSP from a given class of traffic. Two algorithms currently described in DSTE Requirements document: Explicit maximum allocation algorithm • Maximum allowable bandwidth usage of each class is being explicitly specified Russian doll algorithm • Specification of maximum allowable usage is being done cumulatively

  3. Class 1 Class 2 Class 3 Class 1 Classes 1 and 2 Classes 1, 2, & 3 Illustration of the Algorithms Explicit maximum allocation algorithm Russian doll algorithm Class 1 has highest priority, class 3 lowest

  4. Methodology for Comparison • Based on a Markov Chain model described in • W. S. Lai, “Traffic Engineering for MPLS,” Internet Performance and Control of Network Systems III Conference, SPIE Proceedings Vol. 4865, pp. 256-267, Boston, Massachusetts, USA, 29 July-1 August 2002. • http://www.columbia.edu/~ffl5/waisum/bcmodel.pdf • To provide uniform treatment of both Explicit Maximum Allocation and Russian Doll algorithms, and a comparison of their merits in a general setting • same model is being applied for both algorithms • only different parametric values are used for different algorithms

  5. Results of Analysis Russian doll algorithm • Allows greater sharing of bandwidth among different classes of traffic • Performs somewhat better under normal conditions • Works well when preemption is enabled Explicit maximum allocation algorithm • Provides more robust service isolation under high load • Does not depend on the use of preemption Preemption • Gives higher-priority traffic some immunity against the overloading of other classes • Results in a higher blocking/preemption for the overloaded class, when compared with a pure blocking environment

  6. Proposal Adopts the explicit maximum allocation algorithm or its variant, such as maximum allocation with reservation, as the default bandwidth constraint model Rationale • The higher degree of sharing allowed in the Russian doll algorithm causes its inability to offer robust service isolation under overload conditions. • Also, it requires use of preemption to operate well – preemption can be disabled as described in the DS-TE Requirements document. • Maximum allocation algorithms do not have these issues.

More Related