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WP2 – D27 TE. Multicast-like approach for optical networks resources optimisation. Multicast approach (I). Unlike point-to-point optical connections ( Unicast ), every new optical connection established is routed not only to the destination node but also to (N) diverse nodes
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WP2 – D27 TE NOBEL WP2 meeting, April 11-13, Madrid
Multicast-like approach for optical networks resources optimisation NOBEL WP2 meeting, April 11-13, Madrid
Multicast approach (I) • Unlike point-to-point optical connections (Unicast), every new optical connection established is routed not only to the destination node but also to (N) diverse nodes • The source node has more than one logical neighbour • The traffic flows from the source node to these destinations are then groomed (at the source node) and transmitted over a single light path to the different end nodes • 1xN passive optical splitters are placed at the optical terminations in order to extend the light path to N destinations NOBEL WP2 meeting, April 11-13, Madrid
1, 2 and 3 are used Multicast approach (II): Example Unicast approach: a new light path is established for each requested connection Up to 4 connections can be allocated on each wavelength 4 5 Upcoming calls to be allocated 2 (1,6) 1 3 (1,7) 2 6 (1,5) 3 1 7 9 8 NOBEL WP2 meeting, April 11-13, Madrid
Only 1 is used Passive optical splitting Multicast approach (II): Example Multicast-like approach 4 5 2 Upcoming calls to be allocated 3 6 (1,6) 1 S (1,7) 1 1 (1,5) 1 7 9 8 NOBEL WP2 meeting, April 11-13, Madrid
Multicast approach (III) • Applying this strategy pursues two main objectives: • Optimisation of the optical channel capacity utilization by grooming at the source node different traffic flows towards different destination nodes into a single wavelength • Resources saving: when compared to a unicast scheme, the total number of transceivers required is lower as optical channels are re-used by allocating different client traffic flows on them • But,passive optical splitters are needed at each termination of the light paths NOBEL WP2 meeting, April 11-13, Madrid
Preliminary simulation case study (I) • The aim of the simulation study has been: • To find out the network conditions (ratio between the client connections required bandwidth and the wavelength capacity, sublambdas) for which the multicast approach performs better than the unicast one • The number of allocated client connections (calls) given a blocking probability target was used as metric for comparison NOBEL WP2 meeting, April 11-13, Madrid
Simulation case study (II) • NSFNET backbone network was used • 14 optical network elements (OXCs) connected by optical fibre links • The calls are routed over a WDM network using an adaptive routing algorithm based on the shortest path algorithm • A cost function taking into account not only the number of hops but also the actual traffic load was defined • A first-fit scheme is used to select the wavelength on each link • Blocking probability was set to 1% • N (number of destinations) = 3 NOBEL WP2 meeting, April 11-13, Madrid
Without WC With WC Simulation results (I) Number of wavelengths per link: 12 As the number of sublambdas increases (>12), the multicast approach performs better (it allows a higher number of allocated connections) NOBEL WP2 meeting, April 11-13, Madrid
Planned Work for Year 2 Study how to physically implement the multicast approach To find out the ratio between granularities and optimal N Simulate different traffic patterns Application of the multicast-like approach to build OVPN NOBEL WP2 meeting, April 11-13, Madrid
TMCMR&A Catalan Network traffic characterization NOBEL WP2 meeting, April 11-13, Madrid
R&A Catalan traffic characterization (I) • Characterization at packet level: • Packet size distribution Input traffic Output traffic NOBEL WP2 meeting, April 11-13, Madrid
R&A Catalan traffic characterization (II) • Characterization at packet level: • Inter Arrival Packet distribution Input traffic H = 0.6015 Output traffic H = 0.6649 NOBEL WP2 meeting, April 11-13, Madrid
1 0.8 0.3 0.25 0.8 0.6 0.2 0.6 0.4 0.15 HT pdf HT pdf HT pdf 0.4 0.1 0.2 0.2 0.05 0 0 0 0-1 3-4 6-7 9-10 12-13 0-0.1 0.3-0.4 0.6-0.7 0.9-1 0-6 18-24 36-42 54-60 Time (s) Time (min) Time (s) R&A Catalan traffic characterization (III) • Characterization at flow level: • A flow was defined by the 5-tuple: IP source address, IP destination address, L4 protocol, source port number and destination port number • IAT and HT distributions Output traffic NOBEL WP2 meeting, April 11-13, Madrid
Planned work for Year 2 • Refinement of the work carried out in WP2 D17 • Packet size distribution • Inter Arrival packets distribution • Modelization of a sintetic traffic generator • Characterization of IAT and HT of the TCP connections for both the input and output traffic NOBEL WP2 meeting, April 11-13, Madrid