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MPLS PATH PROTECTION. Ashish Gupta (98130) Ashish Gupta (98131). Under guidance of Prof. B. N. Jain. What is MPLS ? Path Protection in MPLS Networks Existing Work Our Scheme: Segment Based Protection Research Issues Present Status Targets. Overview. What is MPLS ?.
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MPLS PATH PROTECTION Ashish Gupta (98130) Ashish Gupta (98131) Under guidance of Prof. B. N. Jain
What is MPLS ? Path Protection in MPLS Networks Existing Work Our Scheme: Segment Based Protection Research Issues Present Status Targets Overview
What is MPLS ? • Current IP’s Routing Model • Each router makes independent forwarding decisions based on destination IP address • MPLS: Multi Protocol Label Switching • Applies concept of VC routing • Packet forwarding is done based on Labels • FEC: Destination address prefix, Traffic Engineering tunnel, Class of Service.
Today’s IP Routing Model does not provide guaranteed services => no path protection required MPLS provides guaranteed services => Path needs to be protected Protection against: Link Failure, Node Failure Parameters Involved: Fault detection, Fault localization, Notification, New LSP setup R9 R2 R4 R8 R3 R1 R5 R10 R7 R6 Path Protection in MPLS
r Original LSP Existing Work • Global Path Protection • Local Path Protection • Link Failure • Node Failure • 1+1 Path Protection • Sharing Modes - 1 : 1, 1 : N, M : N Backup LSP
Ingress Seg. 1 Seg 3 Seg. 2 Seg. 4 Our Approach Segment Based Protection (SBP) Divide the path into segments Egress Original LSP Backup Paths
Closest bound on our restoration time (Global) Need to reserve less backup paths (Local) Less Rejection Rate (More capacity of the network) Flexible : Example heterogeneous core Includes Global/Local Path Protection as special cases User of the service (SLA) can set the delay. More delay => larger segments => less resources (cost) Advantages of SBP
A suitable method to detect , locate and notify failure to the segment head node. Signaling schemes - LDP , RSVP - TE Detection : Tradeoff between periodicity and segment length NotificationPerformance An algorithm for Segmentation based approach Constrained based segmentation setup – basis ? How much network state information do we need ? Online vs Offline Algo More considerations in multiple paths Research Issues
Making the backup paths How does our scheme differs from standard methods of making backup paths Constraints will be superset of constraints needed for active path Avoid looping Amount of Reservation needed for backup paths Compare to other algorithms like local restoration No. of rejections in the system Do simulations for above and report the results Report advantages Research Issues
Managing the Labels Ensuring correct labeling mechanisms when backup path is used Buffering in our scheme to reduce packet loss during switchover time Buffer sizes- depending on segment metrics Buffer at each node or only at segment head nodes. ? Research Issues
Understanding the problem Literature survey Identified Research areas Constrain Based Routing Present Status
December 1st 2001 Error detection and notification issues in Segment based protection (SBP) Work out example scenarios using SBP An algorithm for SBP for different types of basis Label management issues in SBP May 1st 2002 Simulations to test performance and resource usage vs. other schemes Explore other issues like Buffering More simulation and analysis for comparison and advantages Documenting our work Future Targets
Segment based path protection in MPLS networks with bounds on packet lossby: Prof B N Jain & Satish Tripathi IEEE Comms Designing Multiprotocol label switching networks by: Jeremy Lawrence (Cisco systems) Generalized MPLS : an overview of signal enhancement and recovery techniques by: Ayan Banerjee, john Darke, et al. MPLS : breaking throughby: bill Michael Papers Dynamic routing of locally restorable Banddwidth Guranteed tunnels using aggregated link usage informationby: Murali Kodilam, T. V. Lakshman (bell labs.) Literature Survey
RFCs & Internet Drafts MPLS Architecture RFC (RFC #3031) draft-ietf-mpls-recovery-frmwrk-03 Path Protection draft-andersson-fast-reroute-frmwrk-00 draft-haskin-mpls-fast-reroute-03 draft-iwata-mpls-shared-fastreroute-00 draft-shandilya-fault-tolerant-lsp-00 draft-shew-lsp-fast-restoration-00 draft-kini-restoration-shared-backup-00 draft-gan-fast-reroute-RSVP-detours-00 Literature Survey
Presentations on MPLS from CISCO Documents on constrained based routing Literature Survey