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IP Routing Architecture Issues with Next-gen Optical Infrastructures. Bryan Lyles (joint work with Tony McAuley, Ravi Vaidyanathan) Dagstuhl Perspectives Seminar: Architecture and Design of the Future Internet. April 16, 2009. Punch line & key messages.
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IP Routing Architecture Issues with Next-gen Optical Infrastructures Bryan Lyles (joint work with Tony McAuley, Ravi Vaidyanathan) Dagstuhl Perspectives Seminar: Architecture and Design of the Future Internet April 16, 2009
Punch line & key messages • The Optics folks are creating flexible, dynamic infrastructures with “low power” switching of gigabits • The current Internet routing architecture (BGP, OSPF, …) is incapable of taking full advantage of this flexibility
Optical infrastructures are becoming highly “flexible” • Dynamic lambda or circuit setup • GMPLS • GLIF • Major e-Science groups • Internet 2, ESNet, GEANTZ, Learn, LHCNet, … • Ethernet over lambda • Think “sources capable of generating lots of bits” • Optical circuit switching is “greener” than current packet switching (no large buffers or routing tables) • Dynamically move computing to power? • Switching is becoming “fast” • See CORONET BAA
Future network architecture Scenario 2: Dynamic optical circuit between gateways A2 Scenario 1 C A CG A3 AG A1 Scenario 3: Dynamic optical circuit between points in different ASs BG Optical links created & deleted on second time scale B1 B • New technology allows rapidly adapting a high speed optical topology in response to application need and environment • Opportunities for much better capacity and QoS
Challenge • There are no automated control plane processes that will achieve the scenarios described in the last slide • Typically some configuration/management plane control is required for the IP topology to converge around the changes in optical topology • E-Science hand configures routes • Even if there were, the current Internet architecture is actively hostile to frequent changing of optical topology • Routing • Addressing • Configuration • (Certainly for BGP) Traded convergence time and flexibility for stability and scalability
Routing Protocols • We all know about BGP problems • Route damping prevents instability • BGP is designed to have slow responsive to route changes • IGPs not much better • Yes the OSPF or IS-IS protocols converge very quickly but they are only part of the process • Computation of new FIBs, • forcing the FIBs out to the line cards, • hold-down timers • You can pipeline the process and continue forwarding if the rate of change is small • But changes affect the entire IGP domain (especially for use of optical links) • Introduction of new links requires new link weights
Moving from • Where we are now • Static topology, static provisioning • Where we want to go • Dynamic topology, dynamic provisioning