Generalized MPLS Premiere Journée Française sur l IETF Papadimitriou

Generalized MPLS Premiere Journée Française sur l’IETF Papadimitriou Dimitri dimitri. papadimitriou@alcatel. be

Table of Content u GMPLS Key Drivers u Evolution of a Standard (from MPLS to GMPLS) u GMPLS n Paradigm and Concepts n Technology n Signalling n TE-Routing u Key Differences between GMPLS and MPLS u What about MPLambda. S ? u Applications and Future GMPLS evolutions u Conclusion Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

GMPLS Key Drivers u u 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 200 ms to < 1 s (today: centralized computation based on restricted scenarios implying restoration time > 5 s) and Signalled Protection in < 50 ms (as specified in ITU-T G. 841) Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

GMPLS Key Drivers (cont’d) u u 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: n b/w network nodes (EMS/control plane) and Centralized NM System n 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 Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

Control and Transmission Plane Evolutions 1970 analog (copper) 1995 today digital (PDH, SDH) optical (analog, but now on fiber) point-to-point wavelength switched opaque Transport plane optical non transparent operator-assisted/centrally managed provisioning burst/packet switched optical automated path setup under distributed control using GMPLS Control/management plane Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

Evolution of a Standard (Scope) IP/MPLS Developments (since 1996) IETF Standards Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

Evolution of a Standard u IETF 46 -48 MPLS: Multi. Protocol Label Switching n n u IETF 48 -49 IP packet based Packet Traffic Engineering (MPLS-TE) MPl. S: Multi. Protocol Lambda Switching n u GMPLS: Generalized MPLS n IETF 50 -51 n u MPLS control applied on optical channels (wavelengths/lambda’s) and IGP TE extensions 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 n n Papadimitriou D. - Alcatel IPO NA (NSG) LMP extended to “passive devices” via LMP-WDM GMPLS covers G. 707 SDH, G. 709 OTN… DNAC - November 2001

Generalized MPLS Paradigm u GMPLS is based on several premises: n maintaining 1: 1 relationship control plane technology and instance with transport plane layer(s) is counter-productive • “integrated IP/MPLS-Optical control plane” concept n 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 p 2 p links (just as Layer-2 IP -over-PPP) n 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 Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

Let’s Be Cautious ! u u u GMPLS “optical” and “optical” GMPLS “protocol” but “protocol suite” … a “philosophy” ? GMPLS (as protocol suite) n tends to “ubiquity” by including MPLS (subset of GMPLS) n applies to ANY control plane interconnection (peer/overlay) and service model (domain/unified) n covers “standard” mainly ITU-T/T 1 X 1 transmission layers • issue: who drives ? Transmission or Control plane ? u GMPLS (as distributed control plane concept) n collaboration with NMS (during transition phase) in particular for first all-optical deployments n next steps NMS limited to SNMP/Policy/VPN and LDAP Services n and after … ? ? ? Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

Let’s Be Cautious ! (cont’d) u Drawbacks and Challenges n n n u “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 n n 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/T 1 X 1, IEEE, etc. Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

Distributed Control Plane Concept Management Plane Network Controller Control Plane Network Device Transport Plane Network Management System Management Channels Control Channels Transport Channels Distributed Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

GMPLS Technology u GMPLS supports five types of interfaces: n n n u GMPLS extends MPLS/MPLS-TE control plane n n u PSC - Packet Switching Capable: IP/MPLS L 2 SC - 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 LSP establishment spanning PSC or L 2 SC 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 n n separation b/w transmission, control and management plane network management using SNMP (dedicated MIB) Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

GMPLS Technology u GMPLS control plane supports: n n u GMPLS control plane architecture includes several extended MPLS-TE building blocks: n n u domain and unified service model overlay, augmented & peer control plane interconnection model (known as overlay and peer models) 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 n n n Link Bundling (TE-Links) Generalized Unnumbered interfaces Extended Explicit Routing Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

GMPLS Signalling u u u 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 n n n u Control/Signalling driven Topology driven Data/Flow driven Constraint-based Routing: n n n strict and loose explicit routing (hop-by-hop not excluded) strict routing limited to intra-area routing ! inter-area routing under specification Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

GMPLS Signalling u Label Space per transport technology (in addition to MPLS) n n n u “Wavelengths” for Lambda LSP SDH/Sonet for TDM LSP G. 709 OTN for TDM ODUk and OCh LSP Signalling Extensions n Label Request including: • LSP Encoding Type • Switching Type • Payload Type n n 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 T 1. 105) • OTN: G. 709 OTN (ITU-T G. 709) and Pre-OTN Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

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 Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

Traffic Parameters and Label Space u Traffic Parameters n Technology “independent” traffic parameters: • Packet • ATM/Frame Relay • MPLambda. S n Technology “dependent” traffic parameters: • TDM: SDH (ITU-T G. 707) and Sonet (ANSI T 1. 105) • Optical: G. 709 OTN (ITU-T G. 709) and Pre-OTN u Extended Label Space (Generalized Label) n n n Wavelength (Waveband) Label Space SDH/SONET Label Space G. 709 OTN Label Space Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

SDH/Sonet Traffic Parameters Signal Type (8 -bits) RCC (8 -bits) NCC (16 -bits) NVC (16 -bits) Multiplier (16 -bits) Transparency (32 -bits) Signal Type u u SDH: LOVC/TUG and HOVC/AUG SONET: VT/VTG and STS SPE/STS-Group Request Contiguous Concatenation (RCC) u u u Standard Contiguous Concatenation Arbitrary Contiguous Concatenation Flexible Contiguous Concatenation Number of components (timeslots) u u Multiplier (multiple connections) Transparency u u u Papadimitriou D. - Alcatel IPO NA (NSG) NCC: Contiguous concatenation NVC: Virtual concatenation RS/Section OH MS/Line OH per OH Byte (on-demand) DNAC - November 2001

SDH/Sonet Label Space u Numbering scheme: n n n 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 (1, . . , N) u u u U (1, . . , 4) K (1, . . 4) L (1, . . , 8) M (1, . . , 10) 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. u 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) u 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)) Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

G. 709 OTN Traffic Parameters Signal Type (8 -bits) NMC (16 -bits) RMT (8 -bits) NVC (16 -bits) Multiplier (16 -bits) Reserved (32 -bits) Signal Type u u DTH: ODU 1, ODU 2 and ODU 3 OTH: OCh at 2. 5, 10 and 40 Gbps Request Multiplexing Type (RMT) u u Number of components u u NMC: Direct Multiplexing NVC: Virtual Components Multiplier (multiple connections) Direct Multiplexing (flexible) Default: no multiplexing (mapping) Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

G. 709 OTN Label Space - Definitions u Label Structure defined as Tree: n Root: OTUk signal and Leaves: ODUj signals (k j) Reserved u k 3 k 2 k 1 3 fields k 1, k 2 and k 3 self-consistently characterising ODUk label space n n n k 1 (1 -bit): unstructured client signal mapped into ODU 1 (k 1 = 1) via OPU 1 k 2 (3 -bit): unstructured client signal mapped into ODU 2 (k 2 = 1) via OPU 2 or the position of ODU 1 tributary slot in ODTUG 2 (k 2 = 2, . . , 5) mapped into ODU 2 (via OPU 2) k 3 (6 -bit): unstructured client signal mapped into ODU 3 (k 3 = 1) via OPU 3 or the position of ODU 1 tributary slot in ODTUG 3 (k 3 = 2, . . , 17) mapped into ODU 3 (via OPU 3) or the position of ODU 2 tributary slot in ODTUG 3 (k 3 = 18, . . , 33) mapped into ODU 3 (via OPU 3) Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

G. 709 OTN Label Space - Examples u u u If label k[i]=1 (i = 1, 2 or 3) and labels k[j]=0 (j = 1, 2 and 3 with 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: n k 3=0, k 2=0, k 1=1 indicates an ODU 1 mapped into an OTU 1 n k 3=0, k 2=1, k 1=0 indicates an ODU 2 mapped into an OTU 2 n k 3=1, k 2=0, k 1=0 indicates an ODU 3 mapped into an OTU 3 n k 3=0, k 2=3, k 1=0 indicates the second ODU 1 into an ODTUG 2 mapped into an ODU 2 (via OPU 2) mapped into an OTU 2 n k 3=5, k 2=0, k 1=0 indicates the fourth ODU 1 into an ODTUG 3 mapped into an ODU 3 (via OPU 3) mapped into an OTU 3 Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

GMPLS TE-Routing Extensions u u u GMPLS based on IP routing and addressing models IPv 4/v 6 addresses used to identify PSC and non-PSC interfaces Re-using of existing routing protocols enables: n n u u u 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) Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

TE-Routing Extensions for SDH/Sonet u TE-Routing information transported n n u TLVs describing capabilities of SDH/SONET links n n u OSPF: Link State Advertisements (LSAs) grouped in OSPF Packet Data Units (PDUs) IS-IS: Link State PDUs (LSPs) 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 Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

TE-Routing Extensions for G. 709 OTN u TE-Routing information transported n n u TLVs describing capabilities of G. 709 OTN links n n u OSPF: Link State Advertisements (LSAs) grouped in OSPF Packet Data Units (PDUs) IS-IS: Link State PDUs (LSPs) 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 Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

Link Management Protocol - LMP u LMP Protocol provides: n n n Control Channel dynamic configuration Control Channel maintenance (Hello Protocol) Link Verification (Discovery, Mis-wiring) Link Property Correlation (Link bundling) Fault Management • detection (using Lo. S/Lo. L/etc. ) • localization/correlation (alarm suppression) • notification u LMP extended at OIF to cover n n n UNI Neighbor and Service Discovery NNI Adjacency, Neighbor and Service Discovery Further elaboration for SDH/Sonet and G. 709 specifics Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

Key Differences with MPLS-TE u Label space(s) including timeslot, wavelength, or physical space while label stacking is NOT supported u Same type of Ingress and Egress LSR interface per LSP u Control Sonet/SDH, G. 709 OTN, Lambda LSP while payload can include G. 707 SDH/Sonet, G. 709 OTN, Lambda, Ethernet, etc. u Bandwidth allocation in discrete units (TDM, LSC and FSC interfaces) u Downstream on demand ordered control (label distribution) u Bi-directional LSP setup (using Upstream Label) u Reduced bi-directional LSP setup latency (using Suggested Label) Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

Key Differences with MPLS-TE (cont’d) u Label Set to restrict the label choice by downstream node (photonic networks w/o wavelength conversion) u Forwarding Adjacencies in addition to Routing Adjacencies u Fast failure notification/location (for LSP restoration) u Provides enhanced recovery mechanisms (control-plane) in case of signalling channel and/or node failure and “graceful restart” Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

What about MPLambda. S ? u Each OXC includes the equivalent of MPLS-capable Label. Switching Router (LSR) n u MPLS control plane is implemented in each OXC Lambda LSP (or Lightpaths) are considered similar to MPLS Label-Switched Paths (LSPs) n Selection of wavelengths (or lambdas) and OXC ports are considered similar to selection of labels u MPLS signaling protocols (such as RSVP-TE, CR-LDP) adapted for Lambda LSP setup/delete/etc. u IGPs (such as OSPF, ISIS) with “optical” traffic-engineering extensions used for topology/resource discovery using IP address space (no “reachability extensions”) Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

GMPLS Application Scope u Optical Internetworking Forum - OIF n n u ITU-T SG 15 n n u Q 12/Q 15: ASTN (G. 807)/ASON Model Q 9/Q 12/Q 15: G. DCM using Traffic Parameters Q 12/Q 15: G. RTG using TE-Routing Extensions Q 9/Q 11/Q 15: G. VBI (LMP-WDM/OLI) ATM Forum n u UNI 1. 0 Signalling Protocol Expected to become major NNI 1. 0 Protocol Suite GMPLS as “control plane” for ATM networks Interoperability Tests n n n OIF UNI Interoperability Test (Super. Comm’ 01 - June’ 01) GMU MPLS/GMPLS Interop Test (October’ 01) New: OIF NNI Interoperability Test (Super. Comm’ 02 - June’ 02) Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

Future Developments u u u Extend connection services to p 2 mp and mp 2 mp GMPLS-based Meshed Protection/Restoration Tackling All-Optical challenges n n u u u 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 n n n performance monitoring/management security and policy ‘optical’ VPN scheduling services billing/accounting Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

References - GMPLS u E. Mannie, D. Papadimitriou et al. , ‘Generalized MPLS Architecture’, Informationa Draft, draft-ietf-ccamp-gmpls-architecture-01. txt, November 2001 u P. Ashwood-Smith, Lou Berger et al. , ‘Generalized MPLS Signaling – Signaling Functional Requirements, ’ Internet Draft, Work in progress, draft-ietf-mplsgeneralized-signalling-06. txt, October 2001 u 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 u 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 u E. Mannie, D. Papadimitriou et al. , ‘Generalized MPLS Extensions for SONET and SDH Control’, Internet Draft, Work in progress, draft-ietf-ccamp-gmplssonet-sdh-02. txt, October 2001 u M. Fontana, D. Papadimitriou et al. , ‘Generalized MPLS Extensions for G. 079 Optical Transport Networks Control’, Internet Draft, Work in progress, draftfontana-ccamp-gmpls-g 709 -02. txt, November 2001 Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

References - (G)MPLS-TE u K. Kompella, Y. Rekhter, “Signalling Unnumbered Links in RSVP-TE”, Internet Draft, Work in progress, draft-ietf-mpls-rsvp-unnum-03. txt, November 2001 u K. Kompella, Y. Rekhter, “Signalling Unnumbered Links in CR-LDP”, Internet Draft, Work in progress, draft-ietf-mpls-crldp-unnum-02. txt, March 2001 u K. Kompella and Y. Rekhter, LSP Hierarchy with MPLS TE, Internet Draft, Work in progress, draft-ietf-mpls-lsp-hierarchy-03. txt, November 2001 u 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 u u u Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

References - MPLS-TE Optical u 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 u B. Rajagopalan et al. , ‘IP over Optical Networks: A Framework, ’ Internet Draft, Work in progress, draft-ietf-ipo-framework-01. txt, July 2001 u 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 u D. Papadimitriou et al. , ‘Non-linear routing impairments in wavelength switched optical networks, ’ Internet Draft, Work in progress, draft-papadimitriou-ipo-nonlinear-routing-impairments-01. txt, November 2001 u D. Papadimitriou et al. , ‘Linear Crosstalk for Impairment-based Optical Routing, ’ Internet Draft, Work in progress, draft-papadim-ipo-impairmentscrosstalk-00. txt, November 2001 u D. Papadimitriou et al. , ‘Enhanced LSP Services’, Internet Draft, Work in progress, draft-papadimitriou-enhanced-lsps-04. txt, July 2001 Papadimitriou D. - Alcatel IPO NA (NSG) DNAC - November 2001

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