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

R4R8

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. 1Seg. 2

Seg 3Seg. 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 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

Literature Survey

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