Multi-Domain Resilience

Multi-Domain Resilience NOBEL WP2 April 11-13, Madrid

Multi-domain Resilience • IDRA model • Aggregated Information • IDRA Exchanged Information • Interdomain Routing Algorithms • Resilience Techniques

IDRA model • A combined Intradomain and Inter-Domain QoSR Model for Optical Networks. • Goal: supply multi-constrained end-to-end optical paths closer to optimality.

IDRA model

IDRA model • IDRAs are responsible for carrying interdomain routing information and deciding within each NSP which path is the best, among the available paths to reach any known destination. • IDRAs exchange the set of offered services and the combined cost to reach any destination

IDRA model • Cost Metric & Services: advertisements flow

IDRA model

Aggregated Information • To each destination, each AS computes the following: • Cost: combined inter and intradomain cost metric. • Protection: number of different paths available for working and protection.

B B A B A A A C C A C (1) (3) (2) Aggregated Information • Lightpath Aggregation Scheme (LAS)

Aggregated Information • Lightpath Aggregation Scheme (LAS) • Aggregated Delay (Dij): • Compute all the lightpaths from node i to node j. • Add the propagation delay of each link for each ligthpath. • Select the minimum value among the values computed in the step 2. • Aggregated number of available wavelength ( ): • Compute all the lightpaths from node i to node j. • Select the minimum number of wavelength per colour that is available in each path. • Select the maximum value among the values computed in the step 2.

Intra-domain Aggregated Information CIA(i)= Represents the intra-domain aggregation of lambdas, which is locally computed by the IDRA within the NSP domain i PIA(i) = Represents the number of different paths availables for working and protection, which is locally computed by the IDRA within the NSP domain i

Interdomain Aggregated Information CID(i)= Represents the inter-domain minimum availability of lambdas, which is locally computed by the IDRA within the NSP domain i PID(i) = Represents the number of different available paths for working and protection, which is locally computed by the IDRA within the NSP domain i

IDRA Exchanged Information • Cost: defining a C(i) cost function C(i)=f(CID, CiA,WA, WD)

IDRA Exchanged Information • Cost • i: represents a NSP domain in the path from the source domain S to the destination domain D • C(i+1): corresponds to the inter-domain aggregation of lambdas advertised by the IDRA within the NSP domain (i+1) • wA: weight of the intra-domain cost, which is locally assigned by the NSP i • wD: weight of the inter-domain cost, which is locally assigned by the NSP i

IDRA Exchanged Information • Protection: number of different paths available for working and protection. P = < PID, PIA >

Interdomain Routing • Development of combined intra-domain and inter-domain QoS Routing algorithms supporting end-to-end resilience

Interdomain Routing • Source Routing • SPF • Don’t care about Cost and Protection. • Only the number of hops are considered. • BC (Best Cost) • Minimize Cost parameter. • Returns a working path. • HS (Highest Survivability) • Maximize Protection parameter • Several possibilities

Resilience Techniques • (Fast) Re-Route • Dedicated Protection (1+1, 1:1) • Shared Protection • p-Cycles

Work Plan summary • Definition of Multi-Domain networks • Single Layer • Multi-Layer • Defining intra-domain information to be aggregated • Cost, resilience,.. • Defining inter-domain information to be exchanged • Cost, intra-domain aggregated information,.. • Defining Inter-Domain routing algorithms + Resilience Techniques • Study on how the inaccuracy routing information, due to both the aggregation process and the information update delay, influences the resilience techniques • End-to-end vs. domain-by-domain resilience • How the number and the size of domains affect the set up of working and backup paths • …..

Multi-Domain Resilience