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GMPLS optical networks

GMPLS optical networks. Malathi Veeraraghavan Professor Charles L. Brown Dept. of Electrical & Computer Engineering University of Virginia mvee@virginia.edu ETRI, Korea Feb. 2009. GMPLS: Generalized MultiProtocol Label Switched networks (MPLS, SONET, WDM, SDM, VLAN). Outline.

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GMPLS optical networks

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  1. GMPLS optical networks Malathi Veeraraghavan Professor Charles L. Brown Dept. of Electrical & Computer Engineering University of Virginia mvee@virginia.edu ETRI, Korea Feb. 2009 GMPLS: Generalized MultiProtocol Label Switched networks (MPLS, SONET, WDM, SDM, VLAN)

  2. Outline • Telcom “transport network” • Cheetah vs. Dragon Approach • Theoretical concepts • GMPLS networks • Technologies, off-the-shelf switches, control-plane protocols • State of the art on different applications & networks • Commercial • Research-and-Education (REN) networks

  3. Spectrum of services Leased lines are used to connect IP routers. Network that offers leased line service is called “transport network” by telcom industry Leased line IP Circuit technologies: time/frequency division multiplexing PDH: T1, T3 switch: Digital Cross Connect (DCS) SONET/SDH: OC3-OC768 Switch: SONET/SDH crossconnects DWDM: OTU1-OTU3 Switch: optical WDM crossconnects Packet technologies: virtual circuit switches ATM MPLS Carrier-grade Ethernet All the above: Data-plane technologies

  4. IP and leased line service deployment Leased line Telco service provider (transport network) owns circuit/VC switches Circuit or virtual circuit (VC) switch Internet service provider or enterprise owns IP routers IP Router

  5. Management plane (in transport network) (2) NMS computes path with available bandwidth Network management system (1) Admins use Web interface to request leased line creation (3) NMS sends provisioning signals to each switch on path using SNMP/CLI/TL1 Customer edge device Customer edge device Customer edge device switch controller has minimal software (SNMP agent, CLI/TL1 parser) Customer edge device Customer edge device

  6. Spectrum of services New service: rapid provisioning Leased line IP Verizon Bandwidth-on-Demand (BoD)

  7. Management plane + control plane (2) NMS still computes path with available bandwidth Network management system (1) Admins use Web interface to request leased line creation (4) hop-by-hop distributed signaling for circuit/VC provisioning (3) TL1/CLI to edge node Customer edge device Customer edge device Customer edge device switch controllers have RSVP-TE software Customer edge device Customer edge device

  8. Progress made in telcom industry • Data-plane progress • Excellent: interesting new switching technologies being invented for transport networks • Control-plane • Switch controllers implement RSVP-TE capable of distributed route computation and admission control • But only provisioning phase is distributed • Requests for circuits/VCs are still handled through management plane with involvement of administrators even in “Dynamic” scenarios • Why is this an issue? • Limits access to “transport” circuit/VC network

  9. Difference with R&E thinking (2) scheduler computes path with available bandwidth Scheduler (1) application software running at end host initiates request for circuit/VC (3) TL1/CLI to edge node (4) hop-by-hop distributed signaling for circuit/VC provisioning external controller (3a) switch controllers have RSVP-TE software Enterprise (3a) configure router to filter packets for long flow on to circuit/VC

  10. Effect of opening up access to circuit/VC “transport” network • Application software running on end hosts deep inside enterprises can access dynamic circuit/VC services of the backbone transport network • Circuit network reach does not need to extend all the way to the desktop • With additional high-speed line from enterprise edge router into transport network, high-speed access can be enabled for short durations • High call volume of setup/release: automatic generation of calls by software • New applications!

  11. Spectrum of services New services eScience Leased line Verizon BoD IP 10G POTS • Book-ahead (BA) mode • call duration specified • Current solution: • centralized per-domain path computation/admission control • Low call handling volume • Plain Old Telephone Service (64kbps) • Immediate-Request (IR) mode • unspecified call duration • Low call setup overhead • ( holding times can be shorter) • Distributed path computation/admission control • High call handling volume OSCARS/DRAGON CHEETAH

  12. Outline • Telcom “transport network” • Cheetah vs. Dragon Approach • Theoretical concepts • GMPLS networks • Technologies, off-the-shelf switches, control-plane protocols • State of the art on different applications & networks • Commercial • Research-and-Education (REN) networks

  13. Observations • "Many e-science experiments ... are optimized to provide maximum throughput to a few facilities, as opposed to moderate throughput to millions of users, which is the raison d'etre for commercial networks." • Networks should be scalable: • Metcalfe's statement: Value of a network increases exponentially with the number of users

  14. Key difference between DRAGON and CHEETAH • DRAGON focus: • For eScience • Small number of users • High throughput to a few facilities • Transfer technology to Internet2 • Implement and deploy software for book-ahead reservations and circuit provisionining by teaming with ESNet and DANTE • CHEETAH focus: • General-purpose commercial network goal to bring GMPLS services to millions of users • But not with just moderate throughput, but also high-rate • Analyze GMPLS network bandwidth sharing modes (BA + IR) • Implementation: IR

  15. Background • Types of switches • Types of bandwidth-sharing modes • IP networks vs connection-oriented (GMPLS) networks • Tradeoffs in GMPLS network modes • Immediate-request mode (e.g., Plain Old Telephone Service) • Book-ahead (advance-reservation)

  16. Types of switches GMPLS network switches

  17. Difference between bandwidth (BW)-sharing modes • In connectionless networks (e.g., IP) • Pre-1988 IP network: • Just send data without reservations or any mechanism to adjust rates  congestion collapses in the Internet in the 80s! • Van Jacobson's 1988 contribution: • Added congestion control to TCP • Sending TCP adjusts rate • TCP congestion-control pros and cons: • Pros: Proportional fairness and high utilization • Cons: No rate guarantees & No temporal fairness (job seniority) • In connection-oriented networks (e.g., GMPLS) • Key: Admission control

  18. Bandwidth sharing modes in GMPLS networks • Can execute admission control in two ways: • Bufferless (immediate-request) • With buffers (book-ahead is effectively the same as having buffers to hold calls to start in the future) • Immediate-request: M/G/m/m model • m: number of channels on a link (servers) • if all channels are occupied, reject call • Book-ahead: M/G/m/p model • p: max number in system: advance-reservation window K = p/m timeslots • waiting time and call blocking • K cannot be : need to block calls if per-server traffic intensity can be > 1 • Or engineer the system so per-server traffic intensity ≤ 1 • Difference: • Not as the names suggest: IR calls need bandwidth immediately • Misconception: BA with book-ahead time of “now”  IR  NOT TRUE • Instead, call duration needs to be specified to support BA mode • For IR mode, applications do not need to specify duration

  19. r m ua 4 17 117 24.8% 58.2% 84.6% 1 10 100 IR mode: M/G/m/mErlangB formula r: offered traffic load in Erlangs : call arrival rate 1/:mean call holding time r/m: per-server traffic intensity m: number of circuits Pb: call blocking probability ub: utilization For a 1% call blocking probability, i.e., Pb = 0.01 If m is small, high utilization can only be achieved along with high call blocking probability

  20. Comparison of Immediate-Request (IR) and Book-Ahead (BA) schemes • Example • To achieve a 90% utilizationwith a call blocking probability less than 10% • BA-First schemes are needed when m < 59 • To achieve a 90% utilization with a call blocking probabilityless than 20% • BA-First schemes are needed when m < 32 U: utilization K: number of time periods in advance-reservation window Link capacity C = 10Gbps m = 10 if per-call allocation = 1Gbps m=10, K=10, U = 80%: PB = 0.4% m=10, U = 80%: PB = 23.6% m=100, U = 80%: PB= 0.4% BA IR

  21. Bandwidth sharing mechanismsin GMPLS networks Needed if per-call circuit rate is a large fraction of link capacity (e.g., 1Gbps circuits on a 10Gbps link, m = 10) Bandwidth sharing mechanisms Book-ahead Immediate-request call duration specified unspecified call duration BA-n/BA-First VBDS (Varying-Bandwidth Delayed Start) session-type requests: BW, duration data-type requests: file size (can assign any rate, even vary rate in different time ranges) BA-n BA-First Users specify a set of n call-initiation time options Users are given first available timeslot X. Zhu, Ph.D. Thesis, UVA, http://www.ece.virginia.edu/mv/html-files/students.html

  22. Relate BW sharing modes to network types

  23. References on bandwidth sharing modes • IR mode for file transfers with moderate-BW allocation (100Mbps on 10Gbps link) • X. Fang and M. Veeraraghavan, “On using a hybrid architecture for file transfers,” acceptedto IEEE Transactions on Parallel and Distributed Systems, 2009. • X. Fang and M. Veeraraghavan, On using circuit-switched networks for file transfers,” in IEEE Globecom, New Orleans, LA, Nov. 2008. • X. Zhu, X. Zheng, and M. Veeraraghavan, "Experiences in implementing an experimental wide-area GMPLS network,"IEEE Journal on Selected Areas in Communications (JSAC), Apr. 2007. • M. Veeraraghavan, X. Fang, and X. Zheng, “On the suitability of applications for GMPLS networks,” in IEEE Globecom, San Francisco, CA, Nov. 2006. • Large-scale deployment of BA mode: (mean waiting time, blocking rate) • X. Zhu and M. Veeraraghavan, "Analysis and Design of Book-ahead Bandwidth-Sharing Mechanisms," IEEE Transactions on Communications, Dec. 08. • X. Zhu, M. E. McGinley, T. Li, and M. Veeraraghavan, "An Analytical Model for a Book-ahead Bandwidth Scheduler," in IEEEGlobecom Washington, DC, Nov. 2007. Heterogeneous rate allocation

  24. Is an opportunity being missed if distributed IR bandwidth sharing mode is not explored? • Yes. Four reasons: • Increase end-to-end rate relative to IP service; possible in the presence of admission control (programmable patch panels to share ports) • Enable the creation of large-scale circuit/VC networks with moderate-rate circuits that can support a brand new class of applications • economic value for the networking industry • A "reservations-oriented" mode of networking to complement today's connectionless Internet • analogy: airlines complement roadways • Alternative pricing models for bandwidth • Leased lines and IP service are at two extremes • Usage based pricing • Dedicated (moderately high) bandwidth for short durations instead of low bandwidth for all time

  25. To increase end-to-end rate • Problem: • WDM allows 40Gbps/channel with 80 channels/port • But, end-to-end rate is still on the order of tens of Mbps • Why? Access link rates: both for enterprises and residences • Inter-domain link cost: • Internet2 charges $250K/year for a 1Gbps Ethernet connection • Why so high? High router port cost and no sharing • Router port cost: • One-port 10Gbps or ten-port 1Gbps interface card costs $150-200K • 2007 data for local access links in US: • 1.5M T1, 183K T3, 44K OC3, 21K OC12, 2K OC48 and 2.5K OC192 • Add leased lines to terminate on a space-division switch - for moderate rate, connect to sub-Gbps ports • With admission control for ports, connect high-speed link for short duration for single flows based on request from file-transfer apps.

  26. What "brand new class of applications?" • Moderate-bandwidth • Video: “Harry Potter” application, multiple-cameras/automated cameraman for video-tel/conf, distance-learning, virtual reality • Cloud computing, gaming • Teleoperations, telemedicine • High-bandwidth, short-held calls • Web, P2P, storage, CDN file transfers

  27. Outline • Cheetah vs. Dragon Approach • Theoretical concepts • GMPLS networks • Technologies, off-the-shelf switches, control-plane protocols • State of the art on different applications & networks • Commercial • Research-and-Education (REN) networks

  28. GMPLS related technologies • GMPLS networks • Data-(user-) plane protocols • packet-switched: MPLS, VLAN Ethernet (PBBTE) • circuit-switched: SONET/SDH, WDM, SDM (space div. mux) • Control-plane protocols: • RSVP-TE: signaling protocol • OSPF-TE: routing protocol • LMP: link management protocol • Internetworking: Ethernet-over SONET/MPLS/WDM • GFP, VCAT, LCAS for SONET/SDH • PWE3 for MPLS networks • Digital wrapper for OTN

  29. Why internetworking? • GMPLS networks do not exist as standalone entities as data-sourcing end hosts do not have MPLS, SONET, WDM NICs • Instead they need to be internetworked with Ethernet interface cards: • Common usage: IP layer internetworking • IP routers with Packet-over-SONET (PoS) interfaces • Newer usage: Ethernet layer internetworking • Ethernet over MPLS/SONET/WDM/SDM • Port-mapped • VLAN-mapped (probably not supported with SDM) • Ethernet interface could be on hosts or routers

  30. Off-the-shelf GMPLS switches

  31. GMPLS control-plane scope • RSVP-TE and OSPF-TE do not have parameters to support admission control for BA calls • e.g., call duration, optional desired call-initiation time • Strengths: • Distributed routing and call setup/release functions for high-call volume IR calls • OSPF-TE (in each switch controller) • Loading conditions shared only intra-area • Link-state + Distance vector (even basic OSPF) • RSVP-TE (in each switch controller) • Route computation and admission control • CSPF can be done only intra-area by ingress switch • Any switch could be an ingress switch – hence highly scalable • Switch fabric configuration (i.e., provisioning)

  32. Control-plane for BA calls • Run an external scheduler to perform • path computation and admission control for future start time • add authentication and authorization • Centralized scheduler - one per domain • Inter-domain scheduler-to-scheduler protocol: • Abstracted topology exchange • Reservation phase (path computation + admission control) • Signaling phase (not clear why RSVP-TE is not used interdomain) • Intradomain • Provisioning phase: RSVP-TE is used • OSPF-TE data is read out from switch controllers by scheduler for intra-domain path computation • Not a scalable solution to support short-duration, high-BW calls

  33. Outline • Cheetah vs. Dragon Approach • Theoretical concepts • GMPLS networks • Technologies, off-the-shelf switches, control-plane protocols • State of the art on different applications & networks • Commercial • Research-and-Education (REN) networks

  34. Spectrum of services New services Leased line eScience IP 10G POTS Verizon BoD

  35. Commercial uses • Semi-permanent MPLS virtual circuits • Traffic engineering • Voice over IP • QoS concerns: telephony has a 150ms one-way delay requirement (with echo cancellers) • Business or service provider interconnect • interconnecting geographically distributed campuses of an enterprise • interconnecting wide-area routers of an ISP service provider

  36. Traffic engineering (TE) • Since BGP and OSPF routing protocols mainly spread reachability information, routing tables are such that some links become heavily congested while others are lightly loaded • MPLS virtual circuits are used to alleviate this problem • e.g., NY to SF traffic could be directed to take an MPLS virtual circuit on a lightly loaded route avoiding all paths on which more local traffic may compete • This is an application of MPLS VCs without bandwidth allocation

  37. Business or service provider interconnect (leased lines) • Multiple options: • TDM circuits (traditional private line, T1, T3, OC3, OC12, etc.) • Ethernet private line • point-to-point (Ethernet over MPLS/SONET/WDM) • VPNs (called Virtual private LAN service) • MPLS VPNs • WDM lightpaths • Dark fiber

  38. Dynamic circuits/virtual circuit(GMPLS control-plane) • Commercial: • fast restoration • circuit/VC setup delay significant • rapid provisioning • Verizon: Bandwidth on Demand (Just-in-Time Provisioning) • AT&T: Shared mesh networks • Customer Applications for dynamic network configuration • Key industries: Financial, Media & Entertainment • Corporate Utility Backbone Networks (e.g. reconfigure for disaster recovery) • Distribution of real-time content (e.g., Video) • Level3: Vyvx service

  39. Spectrum of services New services eScience Leased line Verizon BoD IP 10G POTS • Book-ahead (BA) mode • call duration specifie d • Current solution: • centralized per-domain path computation/admission control • Low call handling volume OSCARS/DRAGON

  40. Research & Education(G)MPLS networks • Internet2’s Dynamic Circuit network • NSF-funded DRAGON • DOE's ESnet - Science Data Network • DOE's Ultra Science Network (USN)

  41. Internet2 DWDM network Infinera DWDM system http://events.internet2.edu/speakers/speakers.php?go=people&id=178 Rick Summerhill talk (10/11/2007)

  42. Internet2 Dynamic Circuit (DC) network Ciena CD-CI Eth-SONET switch http://events.internet2.edu/speakers/speakers.php?go=people&id=178 Rick Summerhill talk (10/11/2007)

  43. Internet2 IP-routed network IP-router-to-router links on one wavelength SONET switch-to-switch links on another wavelength Ciena CD-CI Eth-SONET switch Juniper T640 IP router http://events.internet2.edu/speakers/speakers.php?go=people&id=178 Rick Summerhill talk (10/11/2007)

  44. Equipment at each PoP http://events.internet2.edu/speakers/speakers.php?go=people&id=178 Rick Summerhill talk (10/11/2007)

  45. Control-plane software(for DC network) • OSCARS implemented in InterDomain Controller (IDC) - one per domain • Abstracted topology exchange • Interdomain scheduling • Interdomain signaling (for provisioning) • DRAGON (intradomain control-plane) • Used in Internet2’s DC network • Intradomain routing, path computation, signaling (for provisioning)

  46. OSCARS • On-demand Secure Circuits and Advance Reservation System (OSCARS) • DOE Office of Science and ESnet project • Co-development with Internet2 • Web Service based provisioning infrastructure, which includes scheduling, AAA architecture using X.509 certificates • Extended to include the DICE IDCP • Reservations held in SQL database • Recall no support for book-ahead in GMPLS control protocols • http://www.es.net/oscars/index.html http://www.csm.ornl.gov/workshops/NetworkingResearchChallenges/agenda.html Talk by Tom Lehman, Sep. 28, 2008

  47. DRAGON • Washington DC metro-area network: • Adva (old Movaz) WDM switches and Ethernet switches (G.709) • Control-plane software: • Network Aware Resource Broker – NARB • Intradomain listener, Path Computation • Virtual Label Swapping Router – VLSR • Implements OSPF-TE, RSVP-TE • Run on control PCs external to switches (since not all switches implement these GMPLS control-plane protocols) • Communicates with switches via SNMP, TL1, CLI to configure circuits. • Client System Agent – CSA • End system software for signaling into network (UNI or peer mode) • Application Specific Topology Builder – ASTB • User Interface and processing which build topologies on behalf of users • Topologies are a user specific configuration of multiple LSPs http://dragon.east.isi.edu

  48. Open Source DCN Software Suite • OSCARS (IDC) • Open source project maintained by ESNet and Internet2 • Uses WDSL, XML, SQL database to store reservations • Reservations accepted with 1 minute granularity • DRAGON (DC) • NSF-funded Open source project maintained by USC ISI EASTand MAX • Version 0.4 of DCNSS current deployed release • https://wiki.internet2.edu/confluence/display/DCNSS • DCN workshops offered for training: • http://www.internet2.edu/workshops/dcn/index.html http://www.csm.ornl.gov/workshops/NetworkingResearchChallenges/agenda.html Talk by Tom Lehman, Sep. 28, 2008

  49. DICE IDCP • Dante, Internet2, CANARIE, ESNet • http://www.controlplane.net • IDCP: InterDomain Controller Protocol • wsdl - web service definition of message types and formats • xsd – definition of schemas used for network topology descriptions and path definitions http://www.csm.ornl.gov/workshops/NetworkingResearchChallenges/agenda.html Talk by Tom Lehman, Sep. 28, 2008

  50. InterDomain Controller (IDC) Protocol (IDCP) • The following organizations have implemented/deployed systems which are compatible with this IDCP • Internet2 Dynamic Circuit Network (DCN) • ESNet Science Data Network (SDN) • GÉANT2 AutoBahn System • Nortel (via a wrapper on top of their commercial DRAC System) • Surfnet (via use of above Nortel solution) • LHCNet (use of I2 DCN Software Suite) • Nysernet (use of I2 DCN Software Suite) • LEARN (use of I2 DCN Software Suite) • LONI (use of I2 DCN Software Suite) • Northrop Grumman (use of I2 DCN Software Suite) • University of Amsterdam (use of I2 DCN Software Suite) • DRAGON Network • The following "higher level service applications" have adapted their existing systems to communicate via the user request side of the IDCP: • LambdaStation (FermiLab) – CMS project on Large Hadron Collider • TeraPaths (Brookhaven) - ATLAS project on Large Hadron Collider • Phoebus http://www.csm.ornl.gov/workshops/NetworkingResearchChallenges/agenda.html Talk by Tom Lehman, Sep. 28, 2008

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