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Generalized MPLS Premiere Journée Française sur l’IETF

Generalized MPLS Premiere Journée Française sur l’IETF. Papadimitriou Dimitri dimitri.papadimitriou@alcatel.be. Table of Content. GMPLS Key Drivers Evolution of a Standard (from MPLS to GMPLS) GMPLS Paradigm and Concepts Technology Signalling TE-Routing

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Generalized MPLS Premiere Journée Française sur l’IETF

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  1. Generalized MPLSPremiere Journée Française sur l’IETF Papadimitriou Dimitri dimitri.papadimitriou@alcatel.be

  2. Table of Content • GMPLS Key Drivers • Evolution of a Standard (from MPLS to GMPLS) • GMPLS • Paradigm and Concepts • Technology • Signalling • TE-Routing • Key Differences between GMPLS and MPLS • What about MPLambdaS ? • Applications and Future GMPLS evolutions • Conclusion

  3. GMPLS Key Drivers • Dynamic and Distributed LSP Explicit TE-Route Computation (today: simulation, manual planning and human action) • Dynamic and Distributed intra and inter-domain LSP Setup/ Deletion/ Modification (today: manual and step-by-step provisioning - doesn’t provide “bandwidth on demand” capability) • Network resource optimization when using a peer interconnection model with multi-layer traffic-engineering and protection/restoration (today: provisioned model implies at least waste of 40% - 60% network resources) • Per-LSP (per-LSP Group) Fast Restoration in 200ms to < 1s (today: centralized computation based on restricted scenarios implying restoration time > 5s) and Signalled Protection in < 50ms (as specified in ITU-T G.841)

  4. GMPLS Key Drivers (cont’d) • Simplified Network control and management (today: each transport layer has its own control and management plane implying waste of 60% - 80% carrier resources) • Removes strong limitations of today proprietary protocols: • b/w network nodes (EMS/control plane) and Centralized NM System • b/w Centralized NM Systems (implying additional proprietary developments) • Conclusion: GMPLS can provide “carrier class” response to new generation transmission networks challenges • Scope: Demystify GMPLS paradigm and related concepts

  5. 1970 1995 today analog (copper) digital (PDH,SDH) optical (analog, but now on fiber) point-to-point wavelength switched burst/packet switched opaque optical non transparent optical Transport plane operator-assisted/centrally managed provisioning automated path setup under distributed control using GMPLS Control/management plane Control and Transmission Plane Evolutions

  6. Evolution of a Standard (Scope) IP/MPLS Developments (since 1996) IETF Standards

  7. Evolution of a Standard • MPLS: MultiProtocol Label Switching • IP packet based • Packet Traffic Engineering (MPLS-TE) • MPlS: MultiProtocol Lambda Switching • MPLS control applied on optical channels (wavelengths/lambda’s) and IGP TE extensions • GMPLS: Generalized MPLS • MPLS control applied on circuits (SDH/Sonet) and optical channel layer and IGP TE extensions • New Protocol introduction: LMP • GMPLS: “separation” b/w Technology dependent and independent • LMP extended to “passive devices” via LMP-WDM • GMPLS covers G.707 SDH, G.709 OTN… IETF 46-48 IETF48-49 IETF50-51

  8. Generalized MPLS Paradigm • GMPLS is based on several premises: • maintaining 1:1 relationship control plane technology and instance with transport plane layer(s) is counter-productive • “integrated IP/MPLS-Optical control plane” concept • maintaining N transport plane layer(s) is counter-productive • only IP/MPLS packet technologies will remain in long-run • ATM layer pushed toward ACCESS networks • SDH/Sonet layer used as framing for p2p links (just as Layer-2 IP-over-PPP) • re-use MPLS-TE as “non-packet” LSP control plane • “lightpath” defines switched path (label space values: wavelengths) • generalize Address Prefix to “non-packet” terminating interfaces • generalize TE concept to “non-packet” resources

  9. Let’s Be Cautious ! • GMPLS  “optical” and “optical”  GMPLS • GMPLS  “protocol” but “protocol suite” … a “philosophy” ? • GMPLS (as protocol suite) • tends to “ubiquity” by including MPLS (subset of GMPLS) • applies to ANY control plane interconnection (peer/overlay) and service model (domain/unified) • covers “standard” mainly ITU-T/T1X1 transmission layers • issue: who drives ? Transmission or Control plane ? • GMPLS (as distributed control plane concept) • collaboration with NMS (during transition phase) in particular for first all-optical deployments • next steps NMS limited to SNMP/Policy/VPN and LDAP Services • and after … ???

  10. Let’s Be Cautious ! (cont’d) • Drawbacks and Challenges • “Full applicability” with multi-service devices in “integrated networks” • Pushing “routing protocols” to some limits … requiring LS IGP enhancements, LMP, etc. • Future GMPLS developments could suffer from a lack of “scientific” coverage • IETF Sub-IP Area WG Positioning • IPO WG plays “driving role” … from (all-)optical viewpoint • CCAMP WG plays “driving role” … from control and (monitoring) measurement protocols • PPVPN WG can be considered here as “service enabler” • Many collaborations with other WG (MPLS, OSPF, ISIS, etc.) and other bodies: ITU-T/T1X1, IEEE, etc.

  11. Network Management System Management Plane Management Channels Network Controller Control Channels Control Plane Network Device Transport Channels Transport Plane Distributed Distributed Control Plane Concept

  12. GMPLS Technology • GMPLS supports five types of interfaces: • PSC - Packet Switching Capable: IP/MPLS • L2SC - Layer-2 Switching Capable: ATM, FR, Ethernet • TDM - Time-Division Multiplexing: Sonet, SDH, G.709 ODU • LSC - Wavelength Switching: Lambda, G.709 OCh • FSC - Fiber Switching • GMPLS extends MPLS/MPLS-TE control plane • LSP establishment spanning PSC or L2SC interfaces is defined in MPLS/MPLS-TE control planes • GMPLS extends these control planes to support this five classes of interfaces (i.e. layers) • As MPLS-TE, GMPLS provides • separation b/w transmission, control and management plane • network management using SNMP (dedicated MIB)

  13. GMPLS Technology • GMPLS control plane supports: • domain and unified service model • overlay, augmented & peer control plane interconnection model (known as overlay and peer models) • GMPLS control plane architecture includes several extended MPLS-TE building blocks: • Signalling Protocols: RSVP-TE and CR-LDP • Intra-domain Routing Protocols: OSPF-TE and ISIS-TE • Inter-domain Routing Protocol: BGP • Link Management Protocol (LMP): new • TE-Routing enhanced scalability and flexibility • Link Bundling (TE-Links) • Generalized Unnumbered interfaces • Extended Explicit Routing

  14. GMPLS Signalling • Downstream on demand Label Allocation • Ingress LSR initiated Ordered Control • Liberal Label retention mode (conservative not excluded) • No distinction b/w Intra and Inter-domain (except policy) • No restriction on LSP establishment strategy • Control/Signalling driven • Topology driven • Data/Flow driven • Constraint-based Routing: • strict and loose explicit routing (hop-by-hop not excluded) • strict routing limited to intra-area routing ! • inter-area routing under specification

  15. GMPLS Signalling • Label Space per transport technology (in addition to MPLS) • “Wavelengths” for Lambda LSP • SDH/Sonet for TDM LSP • G.709 OTN for TDM ODUk and OCh LSP • Signalling Extensions • Label Request including: • LSP Encoding Type • Switching Type • Payload Type • Upstream Label: bi-directional LSP • Label Set: tackle wavelength continuity in AO Networks • Suggested Label: to improve processing • Traffic Parameters including: • TDM: SDH (ITU-T G.707) and Sonet (ANSI T1.105) • OTN: G.709 OTN (ITU-T G.709) and Pre-OTN

  16. Downstream-on-demand Ordered Control Ingress LSR Downstream Label: 8 Suggested Label: 8 Upstream Label: 4 Downstream Label: 5 Suggested Label: 3 Upstream Label: 6 Downstream Label: 9 Suggested Label: 9 Upstream Label: 2 Egress LSR

  17. Traffic Parameters and Label Space • Traffic Parameters • Technology “independent” traffic parameters: • Packet • ATM/Frame Relay • MPLambdaS • Technology “dependent” traffic parameters: • TDM: SDH (ITU-T G.707) and Sonet (ANSI T1.105) • Optical: G.709 OTN (ITU-T G.709) and Pre-OTN • Extended Label Space (Generalized Label) • Wavelength (Waveband) Label Space • SDH/SONET Label Space • G.709 OTN Label Space

  18. Signal Type (8-bits) RCC (8-bits) NCC (16-bits) NVC (16-bits) Multiplier (16-bits) Transparency (32-bits) SDH/Sonet Traffic Parameters Signal Type • SDH: LOVC/TUG and HOVC/AUG • SONET: VT/VTG and STS SPE/STS-Group Request Contiguous Concatenation (RCC) • Standard Contiguous Concatenation • Arbitrary Contiguous Concatenation • Flexible Contiguous Concatenation Number of components (timeslots) • NCC: Contiguous concatenation • NVC: Virtual concatenation Multiplier (multiple connections) Transparency • RS/Section OH • MS/Line OH • per OH Byte (on-demand)

  19. S (1,..,N) U (1,..,4) K (1,..4) L (1,..,8) M (1,..,10) SDH/Sonet Label Space • Numbering scheme: • For SDH, extension of G.707 numbering scheme (K, L, M) • For SONET, field U = 0 = K (not significant). Only S, L and M fields are significant • Each letter indicates a possible branch number starting at parent node in multiplex structure (increasing order from top of multiplex structure) • S - indicates a specific AUG-1/STS-1 inside an STM-N/STS-N multiplex • U - only significant for SDH, indicates a specific VC inside a given AUG-1 • K - only significant for SDH VC-4 (ignored for HO VC-3), indicates a specific branch of a VC-4. • L - indicates a specific branch of a TUG-3, VC-3 or STS-1 SPE (not significant for unstructured VC-4 or STS-1 SPE) • M - indicates a specific branch of a TUG-2/VT Group (not significant for unstructured VC-4, TUG-3, VC-3 or STS-1 SPE (M=0))

  20. Signal Type • DTH: ODU1, ODU2 and ODU3 • OTH: OCh at 2.5, 10 and 40 Gbps Request Multiplexing Type (RMT) • Direct Multiplexing (flexible) • Default: no multiplexing (mapping) Number of components • NMC: Direct Multiplexing • NVC: Virtual Components Multiplier (multiple connections) G.709 OTN Traffic Parameters Signal Type (8-bits) RMT (8-bits) NMC (16-bits) NVC (16-bits) Multiplier (16-bits) Reserved (32-bits)

  21. Reserved k3 k2 k1 G.709 OTN Label Space - Definitions • Label Structure defined as Tree: • Root: OTUk signal and Leaves: ODUj signals (k  j) • 3 fields k1, k2 and k3 self-consistently characterising ODUk label space • k1 (1-bit): unstructured client signal mapped into ODU1 (k1 = 1) via OPU1 • k2 (3-bit): unstructured client signal mapped into ODU2 (k2 = 1) via OPU2 or the position of ODU1 tributary slot in ODTUG2 (k2 = 2,..,5) mapped into ODU2 (via OPU2) • k3 (6-bit): unstructured client signal mapped into ODU3 (k3 = 1) via OPU3 or the position of ODU1 tributary slot in ODTUG3 (k3 = 2,..,17) mapped into ODU3 (via OPU3) or the position of ODU2 tributary slot in ODTUG3 (k3 = 18,..,33) mapped into ODU3 (via OPU3)

  22. G.709 OTN Label Space - Examples • If label k[i]=1 (i = 1, 2 or 3) and labels k[j]=0 (j = 1, 2 and 3with j=/=i), then ODUk signal ODU[i] not structured and mapped into the corresponding OTU[i] (mapping of an ODUk into an OTUk) • Numbering starts at 1 and Label Field = 0 invalid • Examples: • k3=0, k2=0, k1=1 indicates an ODU1 mapped into an OTU1 • k3=0, k2=1, k1=0 indicates an ODU2 mapped into an OTU2 • k3=1, k2=0, k1=0 indicates an ODU3 mapped into an OTU3 • k3=0, k2=3, k1=0 indicates the second ODU1 into an ODTUG2 mapped into an ODU2 (via OPU2) mapped into an OTU2 • k3=5, k2=0, k1=0 indicates the fourth ODU1 into an ODTUG3 mapped into an ODU3 (via OPU3) mapped into an OTU3

  23. GMPLS TE-Routing Extensions • GMPLS based on IP routing and addressing models • IPv4/v6 addresses used to identify PSC and non-PSC interfaces • Re-using of existing routing protocols enables: • benefits from existing intra and inter domain traffic-engineering extensions • benefits from existing inter-domain policy • To cover SDH/Sonet, G.709 OTN transmission technology GMPLS-TE defines technology dependent TE extensions • Increasing scalability using Link bundling and unnumbered interfaces • LSP Hierarchy (and region) through Forwarding Adjacency concept (FA-LSP)

  24. TE-Routing Extensions for SDH/Sonet • TE-Routing information transported • OSPF: Link State Advertisements (LSAs) grouped in OSPF Packet Data Units (PDUs) • IS-IS: Link State PDUs (LSPs) • TLVs describing capabilities of SDH/SONET links • Link Capability and Allocation • LS-MC TLV: Link SDH/SONET Multiplex Capability TLV • LS-CC TLV: Link SDH/SONET Concatenation Capability TLV • LS-PC TLV: Link SDH/SONET Protection Capability TLV • LS-UA TLV: Link SDH/SONET Unallocated Component TLV • Node Capability • RS-I TLV: Router SDH Interconnection TLV • RS-SI TLV: Router SDH-SONET Interworking TLV • Clearly demonstrates rationale for link bundling and unnumbered interfaces

  25. TE-Routing Extensions for G.709 OTN • TE-Routing information transported • OSPF: Link State Advertisements (LSAs) grouped in OSPF Packet Data Units (PDUs) • IS-IS: Link State PDUs (LSPs) • TLVs describing capabilities of G.709 OTN links • At ODU Layer • LD-MP TLV: Link ODUk Mapping Capability TLV • LD-MC TLV: Link ODUk Multiplexing Capability TLV • LD-CC TLV: Link ODUk Concatenation Capability TLV • LD-UA TLV: Link ODUk Unallocated Component TLV • At OCh Layer • LO-MC TLV: Link OCh Multiplexing Capability TLV • LO-UA TLV: Link OCh Unallocated Component TLV • Clearly demonstrates rationale for link bundling and unnumbered interfaces

  26. Link Management Protocol - LMP • LMP Protocol provides: • Control Channel dynamic configuration • Control Channel maintenance (Hello Protocol) • Link Verification (Discovery, Mis-wiring) • Link Property Correlation (Link bundling) • Fault Management • detection (using LoS/LoL/etc.) • localization/correlation (alarm suppression) • notification • LMP extended at OIF to cover • UNI Neighbor and Service Discovery • NNI Adjacency, Neighbor and Service Discovery • Further elaboration for SDH/Sonet and G.709 specifics

  27. Key Differences with MPLS-TE • Label space(s) including timeslot, wavelength, or physical space while label stacking is NOT supported • Same type of Ingress and Egress LSR interface per LSP • Control Sonet/SDH, G.709 OTN, Lambda LSP while payload can include G.707 SDH/Sonet, G.709 OTN, Lambda, Ethernet, etc. • Bandwidth allocation in discrete units (TDM, LSC and FSC interfaces) • Downstream on demand ordered control (label distribution) • Bi-directional LSP setup (using Upstream Label) • Reduced bi-directional LSP setup latency (using Suggested Label)

  28. Key Differences with MPLS-TE (cont’d) • Label Set to restrict the label choice by downstream node (photonic networks w/o wavelength conversion) • Forwarding Adjacencies in addition to Routing Adjacencies • Fast failure notification/location (for LSP restoration) • Provides enhanced recovery mechanisms (control-plane) in case of signalling channel and/or node failure and “graceful restart”

  29. What about MPLambdaS ? • Each OXC includes the equivalent of MPLS-capable Label-Switching Router (LSR) • MPLS control plane is implemented in each OXC • Lambda LSP (or Lightpaths) are considered similar to MPLS Label-Switched Paths (LSPs) • Selection of wavelengths (or lambdas) and OXC ports are considered similar to selection of labels • MPLS signaling protocols (such as RSVP-TE, CR-LDP) adapted for Lambda LSP setup/delete/etc. • IGPs (such as OSPF, ISIS) with “optical” traffic-engineering extensions used for topology/resource discovery using IP address space (no “reachability extensions”)

  30. GMPLS Application Scope • Optical Internetworking Forum - OIF • UNI 1.0 Signalling Protocol • Expected to become major NNI 1.0 Protocol Suite • ITU-T SG15 • Q12/Q15: ASTN (G.807)/ASON Model • Q9/Q12/Q15: G.DCM using Traffic Parameters • Q12/Q15: G.RTG using TE-Routing Extensions • Q9/Q11/Q15: G.VBI (LMP-WDM/OLI) • ATM Forum • GMPLS as “control plane” for ATM networks • Interoperability Tests • OIF UNI Interoperability Test (SuperComm’01 - June’01) • GMU MPLS/GMPLS Interop Test (October’01) • New: OIF NNI Interoperability Test (SuperComm’02 - June’02)

  31. Future Developments • Extend connection services to p2mp and mp2mp • GMPLS-based Meshed Protection/Restoration • Tackling All-Optical challenges • optical routing impairments • transparency • Integrate optical (Layer-1/Layer-0) VPN architecture • Keeping track of G.709 OTN evolutions • Define a global management model including • performance monitoring/management • security and policy • ‘optical’ VPN • scheduling services • billing/accounting

  32. References - GMPLS • E.Mannie, D.Papadimitriou et al., ‘Generalized MPLS Architecture’, Informationa Draft, draft-ietf-ccamp-gmpls-architecture-01.txt, November 2001 • P. Ashwood-Smith, Lou Berger et al., ‘Generalized MPLS Signaling – Signaling Functional Requirements,’ Internet Draft, Work in progress, draft-ietf-mpls-generalized-signalling-06.txt, October 2001 • P. Ashwood-Smith, Lou Berger et al., ‘Generalized MPLS Signaling – RSVP-TE Extensions,’ Internet Draft, Work in progress, draft-ietf-mpls-generalized-rsvp-te-05.txt, October 2001 • P. Ashwood-Smith, Lou Berger et al., ‘Generalized MPLS Signaling – CR-LDP Extensions,’ Internet Draft, Work in progress, draft-ietf-mpls-generalized-cr-ldp-04.txt, July 2001 • E.Mannie, D.Papadimitriou et al., ‘Generalized MPLS Extensions for SONET and SDH Control’, Internet Draft, Work in progress, draft-ietf-ccamp-gmpls-sonet-sdh-02.txt, October 2001 • M.Fontana, D.Papadimitriou et al., ‘Generalized MPLS Extensions for G.079 Optical Transport Networks Control’, Internet Draft, Work in progress, draft-fontana-ccamp-gmpls-g709-02.txt, November 2001

  33. References - (G)MPLS-TE • K.Kompella, Y.Rekhter, “Signalling Unnumbered Links in RSVP-TE”, Internet Draft, Work in progress, draft-ietf-mpls-rsvp-unnum-03.txt, November 2001 • K.Kompella, Y.Rekhter, “Signalling Unnumbered Links in CR-LDP”, Internet Draft, Work in progress, draft-ietf-mpls-crldp-unnum-02.txt, March 2001 • K.Kompella and Y.Rekhter, LSP Hierarchy with MPLS TE, Internet Draft, Work in progress, draft-ietf-mpls-lsp-hierarchy-03.txt, November 2001 • K.Kompella, Y.Rekhter and L. Berger, “Link Bundling in MPLS Traffic Engineering”, Internet Draft, Work in progress, draft-ietf-mpls-bundle-01.txt, November 2001 • K. Kompella et al., “Routing Extensions in Support of Generalized MPLS”, Internet Draft, Work in progress, draft-ietf-ccamp-gmpls-routing-01.txt, November 2001 • K. Kompella et al., “IS-IS Extensions in Support of Generalized MPLS”, Internet Draft, Work in progress, draft-ietf-isis-gmpls-extensions-05.txt, November 2001 • K. Kompella et al. “OSPF Extensions in Support of Generalized MPLS”, Internet Draft, Work in progress, draft-ietf-ccamp-ospf-gmpls-extensions-01.txt, November 01

  34. References - MPLS-TE Optical • D. Awduche et al., ‘Multi-Protocol Lambda Switching: Combining MPLS Traffic Engineering Control With Optical Cross-Connects,’ Internet Draft, Work in progress, draft-awduche-mpls-te-optical-03.txt, April 2001 • B. Rajagopalan et al., ‘IP over Optical Networks: A Framework,’ Internet Draft, Work in progress, draft-ietf-ipo-framework-01.txt, July 2001 • A.Chiu, J.Strand et al., ‘Impairments And Other Constraints On Optical Layer Routing,’ Internet Draft, Work in progress, draft-ietf-ipo-impairments-00.txt, May 2001 • D. Papadimitriou et al., ‘Non-linear routing impairments in wavelength switched optical networks,’ Internet Draft, Work in progress, draft-papadimitriou-ipo-non-linear-routing-impairments-01.txt, November 2001 • D. Papadimitriou et al., ‘Linear Crosstalk for Impairment-based Optical Routing,’ Internet Draft, Work in progress, draft-papadim-ipo-impairments-crosstalk-00.txt, November 2001 • D. Papadimitriou et al., ‘Enhanced LSP Services’, Internet Draft, Work in progress, draft-papadimitriou-enhanced-lsps-04.txt, July 2001

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