1 / 15

IP/MPLS over SDH/GMPLS Recovery Scenarios

IP/MPLS over SDH/GMPLS Recovery Scenarios. Alcatel CIT - France Dominique.Verchere@alcatel.com. Table of Content. Architectural Assumptions Multi-Layer Network architecture System Node architecture Multi-Layer Connection Provisioning Multi Layer Recovery Alternatives

saxton
Download Presentation

IP/MPLS over SDH/GMPLS Recovery Scenarios

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. IP/MPLS over SDH/GMPLS Recovery Scenarios Alcatel CIT - France Dominique.Verchere@alcatel.com

  2. Table of Content • Architectural Assumptions • Multi-Layer Network architecture • System Node architecture • Multi-Layer Connection Provisioning • Multi Layer Recovery Alternatives • SONET/SDH sub-connection recovery • End-to-end SONET/SDH connection recovery • End-to-end IP/MPLS connection recovery • Performance and Comparison of Recovery Scenarios • Network resource requirements • Mean Time to Recovery performance

  3. Network Architecture: COST 266 IP/MPLS Router Routing Domain CORE Router GMPLS X-Connect Egress edge node Ingress edge node • 28 PoPs (Router + X-Connects), STM-16/STM-64 interfaces • 41 WDM Links, Network Connectivity d  3 • Input Traffic Matrix: 5.145 Tbps from IMEC, with Flow entries (voice, data, video) Working Packet LSP LSR1 LSR2 Virtual Topology Backup Packet LSP Packet LSP Intermediate edge node IP / MPLS UNI SDH / GMPLS Egress core node Working TDM LSP Ingress core node CORE Routing Domain Backup TDM-LSP Optical X-Connect

  4. Node Architecture Considered • Edge Router grooms IP traffic: STM-16 or STM-64 • Add/Drop ports for connection to access network • In/Out ports for connection to transport network • OXC transports SDH traffic: STM-16 or STM-64 • Add/Drop ports for injecting/extracting Traffic • In/Out ports for transit Traffic Virtual Topology Egress edge node

  5. UNI End-to-end Connection Provisioning signaling • Packet LSP (IP/MPLS) over SDH LSP multi-hop provisioning • Working (resp. Protecting) LSPs are signaled with (without) resources allocation: (1) & (2) then (3) & (4) • Reach-ability Information are controlled btw Routers and OXCs through UNI C and UNI N respectively • Packet LSPs can be provisioned: (5)/(6) & (7)/(8) Path (5) Path (6) Intermediate Destination Source TE Link Resv (8) Resv (7) Path… (3) Path… (1) Resv… (4) Resv… (2)

  6. SDH LSP_1 SDH LSP_2 (soft-provisioned) Scenario 1: SDH LSP Segment recovery at ingress OXC • Optical TDM LSP shared protection (1:1)N : Soft-Provisioned protecting LSP • Discrete bandwidth reservation VC-4-16c/VC-4-64c granularity • Failure detection/Notification handled by Intermediate OXC with RSVP-TE: • PathErr message vs. Notify message • Ingress OXC Protection set-up, Traffic restoration Switchover & Reversion LSR Add/Drop Ports LSR Add/Drop Ports IP/MPLS Router TE Link IP/MPLS Router UNI Client IP/MPLS LSP_1 UNI Client POS LSR In/Out Ports OXC Add/Drop Ports UNI Network UNI Network STM-x STM-x OXC In/Out Ports OXC In/Out Ports SDH OXC (Ingress OXC) SDH OXC (Egress OXC) NNI NNI NNI STM-x STM-x SDH OXC

  7. Scenario 2: SDH LSP end-to-end recovery at Ingress LSR • Shared protection: (1:1)N : TDM LSPs are dedicated working or back-up • Detection/Notification handled by OXC adjacent to Link failure • Signaling notification are PathErr and Notify msg towards Ingress LSR • Ingress LSR: TDM Protection provisioning , TDM LSP Recovery Switch-over & TDM LSP Reversion LSR Add/Drop Ports LSR Add/Drop Ports TE Link IP/MPLS Router IP/MPLS Router IP/MPLS LSP_1 LSR In/Out Ports UNI Client POS UNI Client UNI Network UNI Network OXC Add/Drop Ports TDM LSP_1 STM-x STM-x OXC In/Out Ports OXC In/Out Ports SDH OXC (Ingress OXC) SDH OXC (Egress OXC) NNI TDM LSP_2 (soft-provisioned) NNI NNI STM-x STM-x SDH OXC

  8. TDM LSP_1 TDM LSP_3 TDM LSP_2 Scenario 3: IP/MPLS LSP recovery (Ingress LSR) • Packet LSP working & detours establishment: Protection Bandwidth Sharing • Failure detection/Notification handled by Intermediate OXC (RSVP-TE Notify and PathErr message towards Ingress LSR) • Ingress LSR: Protected Packet LSP provisioning, Recovery Switch-over & Reversion LSR Add/Drop Ports LSR Add/Drop Ports TE Link IP/MPLS Router IP/MPLS Router IP/MPLS LSP_1 UNI Client POS UNI Client IP/MPLS LSP_2 (detour) soft-provisioned UNI Network UNI Network STM-x STM-x OXC In/Out Ports OXC In/Out Ports SDH OXC (Ingress OXC) SDH OXC (Egress OXC) NNI NNI NNI STM-x STM-x SDH OXC

  9. Network model used TDM connection OTN UNI Destination UNI-C UNI-N Source UNI-C UNI-N UNI-C UNI-C RSVP Session A RSVP Session B OIF UNI GMPLS UNI RSVP Session A Overlay model: Connection triggered w/o EXPLICIT_ROUTE: • UNI Session A Tunnel add.: source UNI-N node ID • If RSVP-TE: Session Tunnel add.: dest. UNI-N node ID • UNI Session B Tunnel address: dest. UNI-C node ID • Source UNI-N computes the path to reach dest. UNI-N and creates an ERO in the outgoing Path messages Failure notification based on PathErr from UNI-N to UNI-C • Proprietary mechanisms Augmented model: Connection triggered with EXPLICIT_ ROUTE: • Session Tunnel address: destination UNI-C node ID Failure Notification directly reported to the sender node based on Notify message • Standardized mechanisms

  10. 1. SDH LSP Segment Protection 2. SDH LSP End-to-end Protection 3. Packet LSP Local Protection: N-HOP FRR Responsible layer for recovery Circuit (SDH/GMPLS) Circuit (SDH/GMPLS) Packet (IP/MPLS) Recovery resource / router driven extra traffic or sharing of recovery resources Soft-provisioned SDH LSP segments with local resource sharing Soft-provisioned SDH e2e LSP resource sharing / LSR driven extra traffic is possible Bandwidth protection using shared detour LSP nested into established SDH e2e LSP Recovery switching initiating entity Edge OXC (UNI-Network) Edge LSR (UNI Client) Edge LSR (UNI Client) Link protection between client LSR & edge OXC Dedicated mechanism (e.g. APS, EPS, other) Inherent Inherent Protection of edge network devices No Yes (with dual homing configuration) Yes (except for source/ destination LSRs) Complexity of implementation Low / Intermediate (if resource sharing) Intermediate High Resource usage efficiency Low (if no OXC driven extra-traffic) Intermediate (sharing between recovery LSP segments) Intermediate High (if good level of protection resources sharing) Low (if no LSR driven extra-traffic) Intermediate (if resource sharing between detour LSPs) Recovery granularity Coarse (per SDH LSP) Coarse (per SDH LSP) Fine (per packet LSP) Recovery Mechanisms Comparison Recovery Scenario

  11. STM-x Interface Number requires • Scenario1 requires EPS for OXC-LSR interfaces • Scenario 3 requires fully provisioned TDM LSPs for the detours

  12. Scenario 2 gain

  13. Time Performance • Recovery speed for (1) and (2) slower than (3) because of an additional «source to destination signaling time» to perform resource activation (consequence of soft- provisioning technique applied in (1) and (2)) • MPLS-based recovery can be used as fallback mechanism in case of GMPLS recovery failure, an hold-off timer has to be applied (before which the IP/MPLS layer should not initiate any recovery attempt)

  14. Conclusion Scenario 2 is optimized thanks to • a better resource sharing capabilities between Edge Routers • An optimized Logical Topology (IP/MPLS) between the router nodes. • A function rich UNI allowing end-to-end signaling sessions.

  15. www.alcatel.com

More Related