p-Cycles: Fast, Flexible, and Efficient Network Survivability



A new book in preparation by Wayne Grover

To be available in 2008 published by John Wiley & Sons, Inc.






Advance Information

p-Cycles are a recent and novel (some would say even fascinating) new architecture for survivability in optical layer transport networks or in MPLS/IP layer client networks.  The basic concept and properties of p-cycles were only discovered in the late 1990s. Since then research activity and industry interest has grown steadily. Enough original research and new knowledge has been produced in the subsequent decade to now support engineering realizations based on the concept, and create the need for a graduate-level teaching and research text to consolidate this new body of knowledge. Wayne Grover has been at center of the advancement and development of p-cycle concepts since inception by himself with a graduate student in 1998. The growing momentum in this field and the accumulation of research on the topic in the last 5-6 years especially creates the need for a single volume that engineers and researchers can access for information and understanding on p-cycles.


This volume will provide text-book level access for working engineers and ongoing researchers to what is already known about p-cycles and will provide a common reference for ongoing discussion and thinking on the topic in the industry and ongoing research. It contains a number of implementation related strategies and techniques and it also serves to dispel common misunderstandings about the topic. 



Metropolitan, national and international fiber-optic based transport networks are actually one of the engineering marvels of 20th century and have become fundamental infrastructure, crucial to current and future economies and societies.  Like many basic civil infrastructures, such as water, roads, power, public health, such engineered systems are almost invisible to the layperson, especially when they work nearly perfectly.  But major and unexpectedly severe economic, personal, and societal impacts arise if these systems are removed even temporarily. Like these other basic infrastructures, the fiber optic transport network is now of fundamental importance to our economy, lifestyles, education, entertainment, finance and so on.  Advances in computing, wireless, mobility, multi-media, HDTV, the Internet, all come to a halt if it were not for the capabilities of the underlying transport network on which they all ride. The public sometimes asks “What about wireless and cell phones, with them we don’t need fiber,” but this is based only on technical unawareness that every cell-phone call relies on fiber optic transport for trunking between switches and base stations to complete the calls.  Similarly, every DSL and cable modem user of high speed Internet access is also a user of the fiber transport backbone.  These “access” technologies, to which we can add phone and bank ATM machines, are best known to us all as users because it is these systems that are “in our face.”  But all of them rely on a single, ubiquitous, relatively unseen transport network operating behind the scenes.”


p-Cycles are a new way to efficiently provide for survivability in these fiber optic backbone networks. The entire technology and theory for p-cycles is less than ten years old. The setting and context is that of what is called telecommunications “transport networking.” Going back more than ten years in this field, a decade long intellectual tug-of-war raged between proponents of the “ring-based” approach to survivability and the “mesh-based” approach. Intense controversy existed between network architects advocating either ring based networking (fast but inefficient) or mesh-based approaches (slower with greater efficiency). Unexpectedly p-cycles emerged and demonstrated the speed of rings and the efficiency (and flexibility) of mesh-based networks at the same time.





1. Introduction and Background


2. The Concept of p-Cycles


3. Optimal Capacity Design of Networks with p-Cycles


4. Application of p-Cycles to DWDM Networks        


5. Heuristic and Algorithmic Approaches to p-Cycle Network Design   


6. “Flow protecting” p-Cycles


7. Hamiltonian p-Cycles and Homogeneous Networks        


8. Virtual p-Cycles in the MPLS Layer for Link and Node Protection   


9. Combined Design of MPLS and WDM Layer p-Cycles


10. Dual-failure Restorability and Strategies for Multiple Quality of Protection Services


11. Availability Analysis of Services in p-Cycle Protected Networks


12. The Protected Working Capacity Envelope Concept using p-Cycles


13. Path-Protecting p-Cycles


14. Node protecting properties and strategies


15. Incremental Re-optimization of p-Cycle networks


16. p-Cycle Implementation: Issues and Solutions




Appendices and Supporting Web site with software