Photonic Network Communications

, Volume 16, Issue 2, pp 169–181 | Cite as

Cross-virtual concatenation for Ethernet-over-SONET/SDH networks

  • Satyajeet S. Ahuja
  • Marwan Krunz


Ethernet-over-SONET/SDH (EoS) is a popular approach for interconnecting geographically distant Ethernet segments using a SONET/SDH transport infrastructure. It typically uses virtual concatenation (VC) for dynamic bandwidth management. The aggregate SONET/SDH bandwidth for a given EoS connection is obtained by “concatenating” a number of equal-capacity virtual channels. Together, these virtual channels form a virtually concatenated group (VCG). In this article, we introduce a new concatenation technique, referred to as cross-virtual concatenation (CVC), which involves the concatenation of virtual channels of heterogeneous capacities. We show that CVC can be implemented through a simple upgrade at the end node, thus utilizing the existing legacy SDH infrastructure. By employing CVC for EoS systems, we show that the SDH bandwidth can be harvested more efficiently than in conventional VC. We consider two problems associated with routing CVC connections: the connection establishment problem and the connection upgrade problem. The goal of the first problem is to compute a set of paths between two EoS end systems such that a total bandwidth demand and a constraint on the differential delay between the paths are satisfied. Among all feasible sets, the one that consumes the least amount of network bandwidth is selected. For this problem, we develop an integer linear program (ILP) and an efficient algorithm based on the sliding-window approach. For the connection upgrade problem, the goal is to augment an existing set of paths so as to increase the aggregate bandwidth, while continue to meet the differential-delay constraint. We model this problem as a flow-maximization problem with a constraint on the delay of the virtual channels with positive flow. We then consider the problem of path selection under imprecise network state information. Simulations are conducted to demonstrate the advantages of employing CVC and to evaluate the performance of the proposed algorithms.


Ethernet-over-SONET Virtual concatenation Optical networks 


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  1. 1.
    ANSI T1.105-2001: Synchronous optical network (SONET): basic description including multiplexing structure, rates and formats (2001)Google Scholar
  2. 2.
    ITU-T Standard G.707: Network node interface for the synchronous digital hierarchy (2000)Google Scholar
  3. 3.
    Acharya, S., Gupta, B., Risbood P., Srivastava, A.: PESO: low overhead protection for Ethernet over SONET transport. In: Proceedings of the IEEE INFOCOM Conference, vol. 1, pp. 175–185, Hong Kong, March 2004Google Scholar
  4. 4.
    Ramamurti, V., Siwko, J., Young, G., Pepe, M.: Initial implementations of point-to-point Ethernet over SONET/SDH transport. IEEE Commun. Mag. 42(3), 64–70 (2004)CrossRefGoogle Scholar
  5. 5.
    Santitoro, R.: Metro Ethernet services—a technical overview. (2003)
  6. 6.
    ITU-T Standard G.7042: Link capacity adjustment scheme for virtually concatenated signals (2001)Google Scholar
  7. 7.
    Srivastava, A., Acharya, S., Alicherry, M., Gupta, B., Risbood, P.: Differential delay aware routing for Ethernet over SONET/SDH. In: Proceedings of the IEEE INFOCOM Conference, vol. 2, pp. 1117–1127, Miami, March 2005Google Scholar
  8. 8.
    Ahuja, S., Krunz, M., Korkmaz, T.: Optimal path selection for minimizing the differential delay in Ethernet over SONET. Comp. Netw. J. 50, 2349–2363 (2006)MATHCrossRefGoogle Scholar
  9. 9.
    Stanley, S., Huff, D.: GFP chips: making SONET/SDH systems safe for Ethernet. LightReading Webinar Id=26778,, Feb. 2004
  10. 10.
    ITU-T Standard G.7041: Generic framing procedure, Feb. 2003Google Scholar
  11. 11.
    Ahuja, R., Magnanti, T., Orlin, J.: Network flows: theory, algorithm, and applications. Prentice Hall Inc. (1993)Google Scholar
  12. 12.
    Chong, E., Maddila, S., Morley, S.: On finding single-source single-destination k shortest paths. In: Proceedings of the Seventh International Conference on Computing and Information (ICCI ’95), pp. 40–47, Peterborough, Ontario, Canada, July 1995Google Scholar
  13. 13.
    Garey, M.R., Johnson, D.S.: Computers and intractability: a guide to the theory of NP-completeness. W.H. Freeman (2000)Google Scholar
  14. 14.
    Korkmaz, T., Krunz, M.: Bandwidth-delay constrained path selection under inaccurate state information. IEEE/ACM Trans. Netw. 11(3), 384–398 (2003)CrossRefGoogle Scholar
  15. 15.
    Lorenz, D.H., Orda, A.: QoS routing in networks with uncertain parameters. IEEE/ACM Trans. Netw. 6(6), 768–778 (1998)CrossRefGoogle Scholar
  16. 16.
    Shaikh, A., Rexford, J., Shin, K.G.: Evaluating the impact of stale link state on quality-of-service routing. IEEE/ACM Trans. Netw. 9(2), 162–176 (2001)CrossRefGoogle Scholar
  17. 17.
    Faloutsos, M., Faloutsos, P., Faloutsos, C.: Power-laws of the Internet topology. In: Proceedings of the ACM SIGCOMM Conference, vol. 29, no. 4, pp. 251–262, Cambridge, Massachusetts, USA, Sept. 1999Google Scholar
  18. 18.
    BRITE: Boston university representative Internet topology generator.

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  1. 1.Department of Electrical and Computer EngineeringThe University of ArizonaTucsonUSA

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