Increasing the Link Utilization in IP over WDM Networks Using Availability as QoS

Increasing the Link Utilization in IP over WDM Networks Using Availability as QoS In this paper, we solve a mapping problem related to supporting two service classes that are differentiated based on their level of protection. The first class of service, called Fully Protected (FP), offers end-users a guarantee of survivability in the case of a single failure; all FP traffic is protected using either a 1:1 or 1 + 1 protection scheme at the WDM layer. The second class of service, called Best-Effort Protected (BEP), is not protected; instead restoration at the IP layer is provided. When a failure occurs, the network restores as much BEP traffic as possible, and thus BEP traffic does not receive any specific guarantees. The FP service class mimics what Internet users receive today. The BEP traffic is designed to run over the large amounts of unused bandwidth that exist in today’s Internet. The motivation of this approach is to give carriers a mechanism for increasing the load carried on backbone networks without reducing the QoS received by existing customers. In order to support two such services, the logical links at the IP layer need to be carefully mapped onto primary and backup paths at the optical layer. We incorporate into our mapping problem a number of practical requirements that reflect constraints that carriers face and policies they want to enforce. For example, we allow the FP demand to be specified via a traffic matrix at the IP layer, we include an overprovisioning factor that specifies the portion of each link that must be left unused, and we incorporate a minimal fairness requirement on how the BEP traffic is allocated among connections. Our goal is to quantify how much BEP traffic can be carried in addition to the FP traffic, without impacting the protection quality of the FP traffic even in the case of failure, and without impacting the FP load. We provide two solutions, one is an optimal solution using an Integer Linear Program (ILP) model, and the other is an algorithm based on the Tabu Search (TS) methodology. Our heuristic algorithm allows us to solve this problem for large networks such as those spanning the continental US. We show that by having two such classes of service, the load on a network can be increased by a factor of 4–7 (depending upon the network). We illustrate that even with overprovisioning and fairness requirements (both of which reduce the total possible BEP load carried), we can still typically triple the total network load. We show that the location of the bottleneck can affect whether or not we see a difference in performance between 1:1 or 1 + 1 protection schemes. Our results illustrate the gain in terms of additional BEP load carried that can be obtained simply due to the upgrade of a single link. Our proposal provides carriers a new vehicle for generating revenue by extracting benefit from all the sources of unused bandwidth in networks. Photonic Network Communications Springer Journals

Increasing the Link Utilization in IP over WDM Networks Using Availability as QoS

Loading next page...
Kluwer Academic Publishers
Copyright © 2005 by Springer Science+Business Media, Inc.
Computer Science; Computer Communication Networks; Electrical Engineering; Characterization and Evaluation of Materials
Publisher site
See Article on Publisher Site


You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial