1. 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. 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. 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. 4 Physical Implementation

5. 5 Synchronization, Control and Header Modification

6. 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. 7 Self-Healing Ring Architecture  Protection against node and link failures using additional switches

8. 8 4-Switch Cyclic Node Design  Intra-nodal system and diverse routing reduces network congestion  Improved network scalability and operation for higher loads

9. 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. 10 Packet Loss Probability

11. 11 End-To-End Delay

12. 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