1 Routing and Resilience in Future Optical Broadband Telecommunications Networks 21 st January 2004 Andrew S. T. Lee Supervisor: Dr. David Harle Broadband and Optical Networks Research Group Dept. of Electronic and Electrical Engineering University of Strathclyde, Glasgow, UK
2 Introduction All-optical physical layer using Optical Packet Switching Synchronous operation at 100 Gbit/s Higher layer Ethernet frames or IP packets are mapped onto multiple optical cells
3 2x2 Optical Buffered Switch Cells are queued using optical buffer Series of 2x2 optical switches and fibre delay lines Logarithmic scalability – discrete buffer lengths Emulates a 2x2 switch with non-optimal delay
4 Physical Implementation
5 Synchronization, Control and Header Modification
6 Self-Routing Networks Each switch makes a fixed routing decision based on packet destination and other header information Queue contention is resolved using deflection routing (different arbitration heuristics)
7 Self-Healing Ring Architecture Protection against node and link failures using additional switches
8 4-Switch Cyclic Node Design Intra-nodal system and diverse routing reduces network congestion Improved network scalability and operation for higher loads
9 Traffic Studies Metrics – buffer depth, packet loss probability, end-to-end delay, ring size, etc. Bernoulli traffic (results shown) Used to contrast different network topologies Bursty traffic models Ethernet/IP frames are carried over the network Impact on packet reordering and sequence integrity Interconnected rings
10 Packet Loss Probability
11 End-To-End Delay
12 Conclusions Multi-switch, bidirectional ring architectures offer best performance at modest buffering Practical node implementation feasible with current technologies High-speed local area and metropolitan area networks High performance computing backbone Possible extensions Multi-wavelength networks using additional componentry, i.e. aggregate of > 1 Tbps Mesh topologies – control and routing issues