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

 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 R2 R3 R6 R4 R8 R7 R1 R10 R9 R5

Global Path Protection Local Path Protection Link Failure Node Failure 1+1 Path Protection Sharing Modes - 1 : 1, 1 : N, M : N r Original LSP Backup LSP

Segment Based Protection (SBP) Original LSP Backup Paths Egress Ingress Seg. 1 Seg. 2 Seg 3 Seg. 4 Divide the path into segments

 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)

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 Notification Performance 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

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

 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. ?

 Understanding the problem  Literature survey  Identified Research areas  Constrain Based Routing

 December 1 st 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 1 st 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

Literature Survey Segment based path protection in MPLS networks with bounds on packet loss by: 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 through by: bill Michael Papers Dynamic routing of locally restorable Banddwidth Guranteed tunnels using aggregated link usage information by: 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