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Resource Optimization in Hybrid Core Networks with 100G Links. Malathi Veeraraghavan University of Virginia [Collaboration with Admela Jukan] Date: Sep. 28, 2009. Outline. Problem statement Hybrid network architecture Traffic monitoring/characterization Traffic engineering
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Resource Optimization in Hybrid Core Networks with 100G Links Malathi Veeraraghavan University of Virginia [Collaboration with Admela Jukan] Date: Sep. 28, 2009
Outline • Problem statement • Hybrid network architecture • Traffic monitoring/characterization • Traffic engineering • Network engineering • Traffic analysis & simulations • DOE testbed • Workplan
Big picture question • As • link rates reach 100Gbps • switching capacities reach tens of Tb/s • Do we need a new backbone network architecture?
Hybrid node architecture Unfolded view Node controller Administrative interface (CLI, TL1) Ethernet control-plane port Signaling (provisioning) protocol SNMP MIB+agents Routing protocol Hybrid node Data plane Layer-3 (IP) router (1Tbps) Output interfaces Input interfaces Carrier Ethernet switch (10Tbps) WDM switch 100Tbps
Hybrid network architecture “put the traffic where the bandwidth is” REF “put the bandwidth where the traffic is” Hybrid Traffic engineering (TE) system Hybrid Network Engineering (NE) system Obtain data Request dynamic circuit setup/release Modify routing metrics and/or write routing table entries Traffic monitoring/ characterization system DOE-implemented control-plane software systems K circuits: IP-routed partition N-K: Dynamic-circuit partition Hybrid Node Hybrid Node Hybrid Node Shared single core pool of N fibers Hybrid Node Hybrid Node REF: Report of US/EU Workshop on Key Issues and Grand Challenges in Optical Networking. Available: http://networks.cs.ucdavis.edu/mukherje/US-EU-wksp-June05-Final-Report.pdf
Traffic monitoring/characterization system Hybrid Traffic engineering (TE) system Hybrid Network Engineering (NE) system Traffic monitoring/ characterization system • Traffic monitoring/characterization system • Reads parameters necessary only for TE/NE applications • Characterizes traffic matrix • Not itself a general-purpose monitoring system such as PerfSONAR • but could interface with such systems to obtain data DOE-implemented control-plane software systems K circuits: IP-routed partition N-K: Dynamic-circuit partition Hybrid Node Hybrid Node Hybrid Node Shared single core pool of N fibers Hybrid Node Hybrid Node Report of US/EU Workshop on Key Issues and Grand Challenges in Optical Networking. Available: http://networks.cs.ucdavis.edu/mukherje/US-EU-wksp-June05-Final-Report.pdf
Hybrid Traffic Engineering system Hybrid Traffic engineering (TE) system Hybrid Network Engineering (NE) system Traffic monitoring/ characterization system • Hybrid Traffic Engineering (TE) system • Obtains data from Traffic monitoring/characterization system • Computes optimal routes for load balancing • Issues CLI commands to hybrid nodes to modify routing metrics • and/or write routing table entries DOE-implemented control-plane software systems K circuits: IP-routed partition N-K: Dynamic-circuit partition Hybrid Node Hybrid Node Hybrid Node Shared single core pool of N fibers Hybrid Node Hybrid Node Report of US/EU Workshop on Key Issues and Grand Challenges in Optical Networking. Available: http://networks.cs.ucdavis.edu/mukherje/US-EU-wksp-June05-Final-Report.pdf
Hybrid network engineering system Hybrid Traffic engineering (TE) system Hybrid Network Engineering (NE) system Traffic monitoring/ characterization system • Hybrid Network Engineering (NE) system • Obtains data from Traffic monitoring/characterization system and • DOE-implemented control-plane software • Determines if thresholds are crossed to trigger setup/release of • dynamic circuits • If triggered, sends request for dynamic circuit setup/release to • DOE-implemented control-plane software • Commands Hybrid TE system to make routing table updates DOE-implemented control-plane software systems K circuits: IP-routed partition N-K: Dynamic-circuit partition Hybrid Node Hybrid Node Hybrid Node Shared single core pool of N fibers Hybrid Node Hybrid Node Report of US/EU Workshop on Key Issues and Grand Challenges in Optical Networking. Available: http://networks.cs.ucdavis.edu/mukherje/US-EU-wksp-June05-Final-Report.pdf
What is today’s backbone network architecture • Two separate networks (separate nodes; separate links) • IP-routed service (black links) • SDN for dynamic-circuit service (blue links) SDN switch IP router Summer 09 ESnet map: http://www.es.net/pub/maps/current.pdf
Nodes and wide-area links • IP routed network • 16 routers (MX960 or M320) • 20 inter-city (WAN) links – 10GbE • SDN network • 17 SDN switches (MX 960) • two in New York, two in Chicago • 29 inter-city (WAN) links – 10 GbE • Metro rings • SUNN, CHIC, NEWY
Future hybrid network:Part of the ESnet topology • For simplicity, let us drop the WDM switch from our hybrid node and just have one connection-oriented switch (e.g., carrier Ethernet, MPLS, WDM, SONET) PNWG DENV 100 GbE 10GbE PNNL LANL SNLA ALBU SUNN ELPA Hybrid node Connection-Oriented (CO) switch IP Router
Hybrid architecture NREL NREL DENV 1 GbE 10 GbE DENV SDN switch IP router CO switch IP router 10 GbE 100 GbE What rate? 10 GbE IP router SDN switch CO switch IP router 1 GbE 10 GbE ALBU ALBU SNLA 10 GbE SNLA 100 GbE LANL LANL dynamic circuit Current: Separate Future: Hybrid
Comparison Link loads are low now; nevertheless 10Gb/s links are required to avoid backbone links from becoming bottlenecks
Questions • Backbone router to backbone router circuits: • bandwidth-limited? • not mandatory to limit circuit bandwidth if CO switch is MPLS or carrier Ethernet • bottleneck link implication on long-flow TCP throughput • if so, what rate? • Access circuits (enterprise-to-backbone): • what rate?
IP datagram flow in future hybrid network PNWG DENV 100 GbE 10GbE PNNL LANL SNLA ALBU SUNN ELPA Hybrid node Connection-Oriented (CO) switch IP Router
Implication • Packet forwarding: • CO switches handle packets at intermediate nodes • Backbone IP routers involved only at source and destination PoPs • “Cut-through” paths • By reducing number of packets handled by IP router: • its’ switching capacity can be smaller • access and backbone circuit rates between access/backbone routers can be lower • low rates will not affect short flows, but will impact long flows • can long flows can be redirected to CO network?
Hybrid architecturefeasibility study • Traffic analysis • Simulations • to enable planning of node size (port speeds, switching capacities)
Traffic analysis • Analyze Netflow data • characterize “short” and “long” flows • flow inter-arrival time distributions • flow duration distributions • need to characterize lengths of silences between long flows generated by an enterprise • determine what applications generate “long” flows
Simulations • Use Netflow data-validated input traffic model for ESnet • Create a simulation model of an alternate “hybrid” ESnet, one in which inter-router links are of lower rates than in deployed network but used only for short flows • Long flows are directed to CO network with dynamic circuit setup between enterprise routers • Obtain performance metrics • short flows • long flows
SNMP traffic analysis • Obtain SNMP link traces for backbone and access links • Are some links that are not on many shortest paths loaded at lighter levels than others? • Time-of-day dependencies? • Correlations? • Stationarity?
DOE-provided testbed • Demonstrate operation of hybrid networks on DOE-provided testbed with 3 to 4 nodes. • Hybrid nodes (provided to us): • IP router (layer 3) + SDN switch (layer 2.5, 2 or 1) • DOE-implemented control-/management-plane software • OSCARS, PerfSONAR • Implemented by us: • Traffic characterization software • Traffic/networking engineering management systems
Work plan • Year 1: Architecture and Analysis • Year 2: Algorithm design and software implementation • Year 3: Prototyping on DOE-provided testbed
Requests to ESnet • Netflow data • Raw SNMP data files • RIBs (BGP and IGP) and IGP metrics • Can a full-mesh of MPLS tunnels - without bandwidth allocations – be created on existing ESnet? • Simplifies the process of generating traffic matrices (LSP SNMP data) • Are there experimental PCs at PoPs for researcher use? • Virtual machines? • PCs connected to both IP router and SDN switch? • Run BWdetail (data-plane experiments) • Is http://netinfo1.es.net to be maintained? If so, the Public Access link gives error messages. Will Level2 access be useful to us?