CONFIDENTIAL © 2004 Procket Networks, Inc. All rights reserved. 4-Feb-14 The 21 st Century Intelligent Network Tony Li, Carl DeSousa

2 CONFIDENTIAL © 2004 Procket Networks, Inc. All rights reserved. 4-Feb-14 Fundamentals Profitability drives the new network New revenues through new applications Video telephony & conferencing Pervasive broadband access HDTV distribution, VOD, gaming FTTP Decreased expenses Capital efficiency Operational efficiency Focus today on network architectures

3 CONFIDENTIAL © 2004 Procket Networks, Inc. All rights reserved. 4-Feb-14 Optical Switching: A Pragmatic Look Optical switching can decrease switching costs New switching layers have associated management costs Demand from full lambda user applications is low Greater need for optical switching in trunking

4 CONFIDENTIAL © 2004 Procket Networks, Inc. All rights reserved. 4-Feb-14 An Example Partial mesh topologies result in transit switching Large traffic aggregates can economically be optically switched at transit points How can we optimally use the lambda topology? Can we provide traffic engineering at the lambda level?

5 CONFIDENTIAL © 2004 Procket Networks, Inc. All rights reserved. 4-Feb-14 Traffic Engineering Commonly used in telephony networks Successful usage in IP networks with MPLS/TE Can we extend this cleanly to the lambda level? Inputs: Node-to-node traffic matrix at the trunk level, time variant Topology, capacity and costs Desired results: (how do we set up switches) Support current offered traffic load Optimal assignments of lambdas to minimize global costs Dynamic recovery to address failures

6 CONFIDENTIAL © 2004 Procket Networks, Inc. All rights reserved. 4-Feb-14 Approaches to dynamic recovery Pre-computation For each possible network failure, compute alternative optimal routing Computationally intensive: scales linearly with number of elements Does not reasonably support multiple failures Dynamic computation Intelligence in the network computes recovery routing Suboptimal computation unless done with global data Slower recovery times Can adapt to multiple failures easily

7 CONFIDENTIAL © 2004 Procket Networks, Inc. All rights reserved. 4-Feb-14 Hybrid computation Combine pre-computation and dynamic computation Pre-compute most significant recovery options for single failures Ignore low-priority recovery Ignore multiple failures Intelligence in the network to dynamically compute remaining cases Centralized computation to recover global optimality for the longer term

8 CONFIDENTIAL © 2004 Procket Networks, Inc. All rights reserved. 4-Feb-14 Benefits and constraints Smooth improvement of efficiency over time Pre-computation provides fast recovery for covered cases Dynamic computation provides coverage for other cases Long term optimization eventually reaches maximal efficiency Effective dynamic computation requires peer model optical network IP layer must know about optical topology and capacity Optical layer must know about traffic priorities Overlay model abstracts optical topology & capacity