Minimizing resource protection in IP over WDM networks: Multi- - PowerPoint PPT Presentation

Minimizing resource protection in IP over WDM networks: Multi- layer Shared Backup Router A. Mayoral, V. López, Ori Gerstel, Eleni Palkopoulou, O. Gonzalez de Dios, J.P. Fernández-Palacios

Index Introduction 01 Multi-layer Restoration Techniques 02 Multi-Layer Shared Backup Router use case 03 Impact on CAPEX reduction 04 Conclusions 05

01 Introduction

Introduction • Current networks operate with separated layers survivability mechanisms § 1+1, 1:1 or M:N Protection § Restoration • Hierarchical Networks Interconnection Routers Traffic is rerouted using FRR … Transit Routers … Access … … … Routers Core Networks Evolution 4 Telefónica I+D

02 Multi-layer Restoration Techniques

Multi-layer Restoration Techniques • Failure in the optical layer: Trials with § GMPLS restoration of “alien” lambdas generated by IP vendors colored ports. § Without alien wavelength, other scenarios are hidden to the IP. • Failure in the IP layer: ComMag Paper § Multi-layer Restoration after a port failure. Jan 2014 § Multilayer Shared Back-up Router after a node failure This work Core Networks Evolution 6 Telefónica I+D

IP port failure restoration A. Without Multilayer Control: One back-up port per link (optical connection preconfigured) B. Multilayer control: One back-up port per node (dynamic optical connection provisioning) A B Back up IP port Core Networks Evolution 7 Telefónica I+D

03 Multi-layer Shared Back-up Router

Multi-layer Shared Backup Routers Interconnection Routers Shared Backup Routers … Transit Routers … … … … Access Routers Core Networks Evolution 9 Telefónica I+D

Multi-layer Shared Backup Routers • Multi-layer restoration consist on using the increased DWDM layer connectivity and dynamicity to recover both layer failures. • Multi-layer restoration allows to increase availability due to the higher number of resources to drive traffic available. Access Region 2 Transit R2 Currently, MPLS survability only can Interconnection be done using pre-stablished links. Transit R1 Access R1 (Fixed neighbours). Transit Transit R3 Backup R3 Access R3 Core Networks Evolution 10 Telefónica I+D

Multi-layer Shared Backup Routers 10G Interface Shared protection router. Single Failure: Connectivity lost and then, ML-Path establishment RT RT RT 100% Traffic recovered in After the failure, less than one 100% 100% a new path is minute stablished with the UNI interface. With this approach CapEx can be decreased because of less backup routers needed. RA RA Region 1 Region 2 Core Networks Evolution 11 Telefónica I+D

04 Impact on CAPEX reduction

Case Study • Table 1 shows the MTTR for protection TR13 2 12 and MLSBR schemes assuming a TR14 1 TR11 3 11 MTBF of 3 years. 13 4 TR3 TR4 16 14 TR12 15 10 • OPEX can be reduced using this 6 TR2 5 9 TR6 TR1 18 protection scheme as MTTR is greater 8 17 7 20 TR5 for the same availability. Add/drop Node 25 26 19 27 OXC 21 TR10 22 TR7 Number of Backup Routers 28 TR9 23 29 Availability 2 3 4 5 6 Protection TR8 24 30 99,99% 33,0 59,2 86,6 110,7 132,6 11,1 99,999% 14,3 31,9 51,6 72,4 91,0 3,4 99,9999% 6,7 17,6 31,9 47,2 63,6 0,1 Table 1: Comparison between MLBSR and Protection in terms of MTTR (days) PEX reduction Core Networks Evolution 13 Telefónica I+D

CAPEX savings • IP layer is dimension with a maximum occupation of 80% for 1+1 protection. 25% 20% • The number of shared back-up router % IP ports reduction 15% can vary. 2012 10% • Two SBRs à 24% of savings in the 2017 5% number of IP ports. 0% 2 3 4 5 6 • The percentage decreases conforms # Shared Backup Routers the number of SBR grows, but savings are conserved in 2017. Core Networks Evolution 14 Telefónica I+D

05 Conclusions

05 Conclusions and next Steps • MLSBR can reduce up to 24% the number of IP ports in the network and it can increase the MTTR. • Following table summarizes the advantages, disadvantages of both approaches and defines requirements to take into account to deploy the solution. Core Networks Evolution 16 Telefónica I+D

Multi-layer Shared Backup Routers 1+1 IP Protection with an additional router Single Failure: Typical Operation: Traffic is moved to backup router. 10G Interface Additional protection router With multi-layer restoration and extra router we can relax even more the MTTR requisites. RT RT RT RT 50% 50% After the first 50% 50% failure an UNI 50% 100% request is used Again we are in the initial to create a new situation with protection backup path. mechanisims ready. RA RA RA RA Región 2 Región 1 Core Networks Evolution 18 Telefónica I+D 1