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Is Lambda Switching Likely for Applications?

Is Lambda Switching Likely for Applications?. Tom Lehman USC/Information Sciences Institute December 2001. Context/Time Frames. Far Future (10 yrs+) New end system architectures which can source/sink 80Gb/s+ Large availability of fiber which can support >1000’s lambda’s per fiber

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Is Lambda Switching Likely for Applications?

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  1. Is Lambda Switching Likely for Applications? Tom Lehman USC/Information Sciences Institute December 2001

  2. Context/Time Frames • Far Future (10 yrs+) • New end system architectures which can source/sink 80Gb/s+ • Large availability of fiber which can support >1000’s lambda’s per fiber • Near Future (5-10 yrs) • Improvements in existing end system architecture • Must live with/use large amounts of non-dispersion compensated fiber currently in place • Following slides will focus on this time frame

  3. Network Component Considerations • Before we discuss network architectures, protocols, and features, lets evaluate what we can expect from the components in this time frame • End Systems • Routers & Switches • Optical capacity

  4. End System/Router/Switch Performance (order of magnitude) • Currently • 2 GHz processors, 128 bit => 250 Gbit/s processing power • 250 MHz SRAM, 128 bit => 32 Gbit/s memory bandwidth • 133 MHz PCIx, 64 bit => 8 Gbit/s I/0 bandwidth • Router/Switch Interfaces => 10 Gbit/s • Near Future? • 10 Ghz processors, 128 bit => Terabit/s processing power • 1 GHz SRAM, 128 bit => 128 Gbit/s memory bandwidth • QDR 133 MHz PCIx, 64 bit => 32 Gbits/s • Infiniban12x => 24 Gbit/s (per full duplex channel) • Router/Switch Interfaces =>40 Gbit/s

  5. Optical Capacity (order of magnitude) • Currently • C Band (1529-1562nm) @50-100Ghz spacing => 64 lambda’s/fiber • 10 Gbit/s/lambda => 640 Gbits/s/fiber • Near Future • 80 Lambda’s/fiber • 40 Gbit/s lambda => 3.2 Terabits/s/fiber • 80 Gbit/s lambda => 6.4 Terabits/s/fiber • End Systems and Router/Switch interfaces will not keep up with the increase in optical speeds • Moore’s law will not allow processor speeds to keep up • End system architecture (complicated OS and protocol stack and slow I/O) will prevent matching speeds • Router switch interfaces beyond 40 Gbit/s will be a challenge (electronic components do not yet exist for those speeds, so gap between optics and electronics will get larger)

  6. Assumption on Component Capabilities • End Systems • Source/sink 24 Gbit/s • End system modifications may include • Direct host memory to NIC card dma features • Complete offload of protocol stack to hardware • Router/Switch Interfaces • 40 Gbit/s • Optical Capacity (per fiber) • 80 lambda/fiber @40 Gbit/s => 3.2 Terabits/s/fiber

  7. Is Lambda Switching Likely for Applications? • No, in the context of end to end lambda switching between applications across the network on a widescale • not enough lambda’s for this to scale • Special applications (e-Science?) may require end to end lambda’s • Yes, in the context of an interface or network connection which provides real time capacity provisioning based on application requests • this could be part of overall QOS scheme • (some) circuit/lambda switched in the core, IP on the edges • Networks need to be able to support widescale deployment of “fast” end systems and also provide guaranteed QOS • Lambda switching could be a key enabling technology

  8. Network Issues • Networks need to provide applications with on demand guaranteed QOS. This should include: • ability for applications to discover/query in real time end to end performance • ability to be guaranteed a level of “performance” on and end to end basis • IP Networks • packet switched networks good for bursty traffic and applications which can live with best effort delivery. • not so good for long flows which require guaranteed performance • currently no well working mechanisms for guaranteed QOS in IP networks. • DiffServ, RSVP, MPLS, IntServ • Circuit switched networks provide QOS, but did not scale well.

  9. GMPLS a solution? • GMPLS may be heading in the right direction • allows MPLS to control multiple devices such as LSRs, SONET ADMs, OADMs, OXCs • Allows network to utilize benefits of packet switched and circuit switched networks. • Bulk of traffic should still be packet switched on an end to end basis • Circuit switched lambda’s could be used for provisioning based on aggregation of application demands • Special applications (e-Science?) may require end to end lambda’s

  10. GMPLS Architecture • IP is the control plane for setting up “layer 2 circuits” IP Router Lambda Switch

  11. QOS in this Environment • The packet switched QOS should be simpler • just guarantees bandwidth? • applications which use this can compensate for loss and jitter (including VOIP) • Circuit switched QOS guarantees bandwidth, delay, jitter • But the same issues that have yet to be solved regarding QOS still need resolution • What is the economic model? Who pays? • How is it enforced? • The monitoring, enforcement, and accounting must be simple. • How is this accomplished across domains? • an ability to create “layer 2” circuits across domains may help this

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