Telecommunication Systems

, Volume 60, Issue 4, pp 485–502 | Cite as

On providing fast protection with remote loop-free alternates

Analyzing and Optimizing Unit Cost Networks
  • Levente CsikorEmail author
  • Gábor Rétvári


Up to not so long ago, loop-free alternates (LFA) was the only viable option for providing fast protection in pure IP and MultiProtocol Label Switching–Label Distribution Protocol networks. Unfortunately, LFA cannot provide protection for all possible failure cases in general. Recently, the Internet Engineering Task Force has initiated the remote loop-free alternates (rLFA) technique as a simple extension to LFA, to boost the fraction of failure cases covered by fast protection. Before further standardization and deployment, however, it is crucial to determine to what extent rLFA can improve the level of protection against single link or node failures in a general IP network, as well as to find optimization methods to tweak a network for 100 % rLFA coverage. In this paper, we take the first steps towards this goal by solving these problems in the special, but practically relevant, case when each network link is of unit cost. We also provide preliminary numerical evaluations conducted on real IP network topologies, which suggest that rLFA significantly improves the level of protection, and most networks need only 2–3 new links to be added to attain 100 % failure case coverage irrespectively of whether link or node protection is considered.


IP Fast ReRoute Remote loop-free alternates Link protection Node protection Heuristics Unit link costs 



The authors thank the support of High Speed Networks Laboratory at BME. This project was supported by TÁMOP 4.2.2.B-10/1-2010-0009 and OTKA-PD 104939 grants. Levente Csikor was supported by the hungarian Sándor Csibi Research Grant.


  1. 1.
    Ahn, G., Jang, J., & Chun, W. (2002). An efficient rerouting scheme for mpls-based recovery and its performance evaluation. Telecommunication Systems, 19(3–4), 481–495. doi: 10.1023/A:1013806925464.CrossRefGoogle Scholar
  2. 2.
    Amund, K., Fosselie, H. A., Čičic, Tarik, Stein, G., & Olav, L. (2009). Multiple routing configurations for fast IP network recovery. IEEE/ACM Transactions on Netwworking, 17(2), 473–486. doi: 10.1109/TNET.2008.926507.CrossRefGoogle Scholar
  3. 3.
    Andersson, L., Minei, I., & Thomas, B. (2007). Ldp specifiaction. RFC 5036.Google Scholar
  4. 4.
    Antonakopoulos, S., Bejerano, Y., & Koppol, P. (2012). A simple ip fast reroute scheme for full coverage. In 2012 IEEE 13th International Conference on, High Performance Switching and Routing (HPSR) (pp. 15–22). doi: 10.1109/HPSR.2012.6260822.
  5. 5.
    Atlas, A., & Zinin, A. (2008). Basic specification for IP fast reroute: Loop-Free Alternates. RFC 5286.Google Scholar
  6. 6.
    Bryant, S., Filfils, C., Previdi, S., & Shand, M. (2007). IP fast reroute using tunnels. IETF DRAFT.Google Scholar
  7. 7.
    Bryant, S., Filfils, C., Shand, M., & So, N. (2012). Remote LFA FRR. IETF DRAFT.Google Scholar
  8. 8.
    Bryant, S., Shand, M., & Previdi, S. (2010). IP fast reroute using Not-via addresses. Internet Draft.Google Scholar
  9. 9.
    Čičic, T. (2006). An upper bound on the state requirements of link-fault tolerant multi-topology routing. IEEE ICC, 3, 1026–1031.Google Scholar
  10. 10.
    Cisco Systems: Cisco ios release 12.0 and network protocols configuration guide (2011).Google Scholar
  11. 11.
    Cisco Systems: Ip routing: Ospf configuration guide, cisco ios release 15.2s—ospf ipv4 remote loop-free alternate ip fast reroute (downloaded: Apr. 2012).Google Scholar
  12. 12.
    Császár, A., Enyedi, G., & Kini, S. (March 2011). Ip fast re-route with fast notification. Internet Draft.Google Scholar
  13. 13.
    Csikor, L., Nagy, M., & Rétvári, G. (2011). Network optimization techniques for improving fast ip-level resilience with loop-free alternates. Infocommunications Journal, 3(4), 2–10.Google Scholar
  14. 14.
    Csikor, L., & Rétvári, G. (2012). IP fast reroute with remote loop-free alternates: The unit link cost case. In Proceedings of the RNDM (pp. 16–22).Google Scholar
  15. 15.
    Csikor, L., Rétvári, G., & Tapolcai, J. (2012). Optimizing igp link costs for improving ip-level resilience with loop-free alternates. Computer Communications. doi: 10.1016/j.comcom.2012.09.004.
  16. 16.
    Enyedi, G., Rétvári, G., & Cinkler, T. (2007). A novel loop-free IP fast reroute algorithm. In EUNICE.Google Scholar
  17. 17.
    Enyedi, G., Szilágyi, P., Rétvári, G., & Császár, A. (2009). IP Fast ReRoute: Lightweight Not-Via without additional addresses. In INFOCOM Mini-conf.Google Scholar
  18. 18.
    Golumbic, M. C. (2004). Algorithmic Graph Theory and Perfect Graphs (2nd ed.). Amsterdam: Elsevier Science.zbMATHGoogle Scholar
  19. 19.
    Gomes, T., oes, C.S., & Fernandes, L. (2011). Resilient routing in optical networks using srlg-disjoint path pairs of min-sum cost. Springer Telecommunication Systems Journal.Google Scholar
  20. 20.
    Hock, D., Hartmann, M., Menth, M., Pioro, M., Tomaszewski, A., & Zukowski, C. (2011). Comparison of ip-based and explicit paths for one-to-one fastreroute in mpls networks. Springer Telecommunication Systems Journal, 1–12. doi: 10.1007/s11235-011-9603-4.
  21. 21.
    Hokelek, I., Fecko, M., Gurung, P., Samtani, S., Cevher, S., & Sucec, J. (Feb 2008). Loop-free ip fast reroute using local and remote lfaps. Internet Draft.Google Scholar
  22. 22.
    Iannaccone, G., Chuah, C.N., Mortier, R., Bhattacharyya, S., & Diot, C. (2002) Analysis of link failures in an ip backbone. In ACM SIGCOMM Internet Measurement Workshop (pp. 237–242).Google Scholar
  23. 23.
    ISO: Intermediate ststem-to-intermediate system (is-is) routing protocol. ISO/IEC 10589 (2002).Google Scholar
  24. 24.
    Iyer, S., Bhattacharyya, S., Taft, N., & Diot, C. (2003). An approach to alleviate link overload as observed on an IP backbone. In INFOCOM.Google Scholar
  25. 25.
    Jarry, A. (2013). Fast reroute paths algorithms. Telecommunication Systems, 52(2), 881–888. doi: 10.1007/s11235-011-9582-5.Google Scholar
  26. 26.
    Juniper Networks: Junos 9.6 routing protocols configuration guide (2009).Google Scholar
  27. 27.
    Knight, S., Nguyen, H.X., Falkner, N., Bowden, R., & Roughan, M. The internet topology zoo. (downloaded: Apr. 2012)
  28. 28.
    Kwong, K.W., Gao, L., Guerin, R., & Zhang, Z.L. (2010). On the feasibility and efficacy of protection routing in ip networks. In INFOCOM, long version is available in Tech. Rep. 2009. University of Pennsylvania.Google Scholar
  29. 29.
    Labovitz, C., Malan, G. R., & Jahanian, F. (1998). Internet routing instability. IEEE/ACM Transactions on Networking, 6(5), 515–528.CrossRefGoogle Scholar
  30. 30.
    Lakshminarayanan, K., Caesar, M., Rangan, M., Anderson, T., Shenker, S., & Stoica, I. (2007). Achieving convergence-free routing using failure-carrying packets. In Proceedings of the SIGCOMM.Google Scholar
  31. 31.
    Lee, S., Yu, Y., Nelakuditi, S., Zhang, Z.L., & Chuah, C.N. (2004). Proactive vs reactive approaches to failure resilient routing. In INFOCOM.Google Scholar
  32. 32.
    Mahajan, R., Spring, N., Wetherall, D., & Anderson, T. (2002). Inferring link weights using end-to-end measurements. In ACM IMC (pp. 231–236).Google Scholar
  33. 33.
    Markopoulou, A., Iannacone, G., Bhattacharyya, S., Chuah, C.N., & Diot, C. (Mar. 2004). Characterization of failures in an ip backbone. In Proceedings of the IEEE Infocom.Google Scholar
  34. 34.
    Médard, M., Barry, R. A., Finn, S. G., & Galler, R. G. (1999). Redundant trees for preplanned recovery in arbitrary vertex-redundant or edge-redundant graphs. IEEE/ACM Transactions on Networking, 7(5), 641–652.CrossRefGoogle Scholar
  35. 35.
    Menth, M., Hartmann, M., Martin, R., Čičic, T., & Kvalbein, A. (2010). Loop-free alternates and not-via addresses: A proper combination for ip fast reroute? Computer Networks, 54(8), 41300–41315. doi: 10.1016/j.comnet.2009.10.020.CrossRefGoogle Scholar
  36. 36.
    Merindol, P., Pansiot, J.J., & Cateloin, S. (2008). Providing protection and restoration with distributed multipath routing. In International symposium on, performance evaluation of computer and telecommunication systems, 2008. SPECTS 2008 (pp. 456–463).Google Scholar
  37. 37.
    Moy, J. (1998). Ospf version 2. RFC 2328.Google Scholar
  38. 38.
    Nagy, M., Tapolcai, J., & Rétvári, G. (2012). Optimization methods for improving ip-level fast protection for local shared risk groups with loop-free alternates. Springer Telecommunication Systems Journal.Google Scholar
  39. 39.
    Pan, P., Swallow, G., & Atlas, A. (2005). Fast reroute extensions to RSVP-TE for LSP tunnels. RFC 4090.Google Scholar
  40. 40.
    Rétvári, G., Csikor, L., Tapolcai, J., Enyedi, G., & Császár, A. (Oct. 2011). Optimizing igp link costs for improving IP-level resilience. In Proceedings of the DRCN (pp. 62–69).Google Scholar
  41. 41.
    Rétvári, G., Tapolcai, J., Enyedi, G., & Császár, A. (2011). IP fast ReRoute: Loop free alternates revisited. In INFOCOM (pp. 2948–2956).Google Scholar
  42. 42.
    Schollmeier, G., Charzinski, J., Kirstädter, A., Reichert, C., Schrodi, K., Glickman, Y., & Winkler, C. (2003). Improving the resilience in ip networks. In Proceedings of the HPSR.Google Scholar
  43. 43.
    Shand, M., & Bryant, S. (2010). IP Fast Reroute framework. RFC 5714.Google Scholar
  44. 44.
    SNDLib: Survivable fixed telecommunication network design library. (downloaded: Apr. 2012).
  45. 45.
    Sterbenz, J., Cetinkaya, E.K., Hameed, M.A., Jabbar, A., Qian, S., & Rohrer, J.P. (2011). Evaluation of network resilience, survivability, and disruption tolerance: Analysis, topology generation, simulation and experimentation. Springer Telecommunication Systems Journal, 1–32. doi: 10.1007/s11235-011-9573-6.
  46. 46.
    Vulimiri, A., Michel, O., Godfrey, P.B., & Shenker, S. (2012). More is less: reducing latency via redundancy. In Hotnets.Google Scholar
  47. 47.
    Zhong, Z., Nelakuditi, S., Yu, Y., Lee, S., Wang, J., & Chuah, C.N. (2005). Failure inferencing based fast rerouting for handling transient link and node failures. In INFOCOM.Google Scholar

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  1. 1.MTA-BME Future Internet Research Group, High Speed Networks Laboratory, Department of Telecommunications and Media InformaticsBudapest University of Technology and EconomicsBudapestHungary

Personalised recommendations