Outline Background: Optical burst switching (OBS Bounds for blocking probability obtained by Overflow Priority Classification Approximation (OPCA)in OBS networks with deflection routing o Effective and ineffective utilizations in obs networks o EBSL-a combination of Emulated-OBS (E-OBS segmentation and least remaining hop-count first (RHF) ●Q&A
Outline Background: Optical burst switching (OBS) Bounds for blocking probability obtained by Overflow Priority Classification Approximation (OPCA) in OBS networks with deflection routing Effective and ineffective utilizations in OBS networks EBSL – a combination of Emulated-OBS (E-OBS), segmentation and least remaining hop-count first (LRHF) Q & A 16
Performance study of oBs networks OCking pr robability Blocking probability= noof lost bursts no of sent bursts Occupied by bursts that: successful ● Utilization transmitted or dumped before reaching the destinations Utilization ∑ number of busy channels in trunk j II number of channels in trunk J: the set of all the trunks in the network G: number of trunks in J
Performance study of OBS networks Blocking probability Utilization no of sent bursts no of lost bursts Blocking probabilit y . . = G number of trunksin J J the set of all thetrunksin the network total number of channelsin trunk j number of in trunk j G Utilization j J : : 1 = busy channels Occupied by bursts that: successfully transmitted or dumped before reaching the destinations 17
Objective To gain insight into the efficiency and performance of obs networks Effective Channels used by bursts that Utilization eventually reach their destinations (EU)T% Goodput Traffic that Utilization(u) succes h y reac riangs % the destinations Ineffective Channels used by bursts that are Utilization du lumped before reaching their destinations
Objective To gain insight into the efficiency and performance of OBS networks Utilization (U) [%] Effective Utilization (EU) [%] Ineffective Utilization (IU) [%] Channels used by bursts that eventually reach their destinations Channels used by bursts that are dumped before reaching their destinations Goodput [Erlangs] Traffic that successfully reach the destinations 18
An EXample ee channe Busy channel occupied by a burst that can reach its destination→EU Busy channel occupied by a burst that dumped before reach its destination IU Node Burst ADNd Burst AD/Node Burst CD/ Nod Burst AD: from a to D through b and c B Burst BD C Burst BD D Burst bd. from b to d through c Trunk 1 Trunk 2 Trunk 3 Burst CD: from C to D U:50 u: 1 B0% AD is duh pe@0% Eu: OC EU:50% EU:100%0 IU:509 :50%
An Example Trunk 1: U: 50% EU: 0% IU: 50% Trunk 2: U: 100% EU: 50% IU: 50% Trunk 3: U: 100% EU: 100% IU: 0% Node A Node B Node C Node D Burst AD Burst AD Burst BD Burst CD Burst BD Free channel Busy channel occupied by a burst that can reach its destination →EU Busy channel occupied by a burst that dumped before reach its destination → IU 19 Burst AD is dumped Burst AD: from A to D through B and C Burst BD: from B to D through C Burst CD: from C to D
Network models 200 868 200 200 324 68 2482 212 80 200 200 272 1036 416 200 node rin 14-node nsfnet With only 3-hop sd pairs With all possible sd pairs
Network Models 20 6-node ring 14-node NSFNet With only 3-hop SD pairs With all possible SD pairs 200 200 200 200 200 200