香港城市大学：PERFORMANCE ANALYSIS OF CIRCUIT SWITCHED NETWORKS（PPT讲稿）

PERFORMANCE ANALYSIS OF CIRCUIT SWITCHED NETWORKS WANG Meiqian (51747598 Supervisor: Dr. WONG, Eric WM Co-supervisor: Prof ZUKERMAN, Moshe Jul.4.2013 Further Credits: V. Abramov. Li Shuo 香港城市大學 City University of Hong Kong

PERFORMANCE ANALYSIS OF CIRCUIT SWITCHED NETWORKS WANG Meiqian (51747598) Supervisor: Dr. WONG, Eric W M Co-supervisor: Prof. ZUKERMAN, Moshe Jul. 4, 2013 Further Credits: V. Abramov, Li Shuo. 1

Outline Why circuit switching Background on existing method Circuit Switched Networks with long-lived and short -ived connections Computation of blocking probability for large circuit switched networks Circuit switched multi-service multi-rate Networks with deflection .q&a 香港城市大學 City University of Hong Kong

Outline • Why circuit switching? • Background on existing method • Circuit Switched Networks with long-lived and short-lived connections • Computation of blocking probability for large circuit switched networks • Circuit Switched Multi-service Multi-rate Networks with Deflection • Q & A 2

Why Circuit Switching(CS >4-5% of global energy is consumed by Internet in 2010. 20 will be consumed in 2023 v CS is more green!! 1. No need for individual treatment of packets 2. Simple in transport no buffering no table look-up no header processing no counting packets 3. No dropping packets at middle of transmission congestion control at the call level 1)RS Tucker, " A Green Internet, IEEE Lasers and Electro-Optics Society, 2008

➢ 4-5% of global energy is consumed by Internet in 2010, 20% will be consumed in 2023 ✓ CS is more Green!! 1. No need for individual treatment of packets. 2. Simple in transport • no buffering • no table look-up • no header processing • no counting packets 3. No dropping packets at middle of transmission. • congestion control at the call level 1) RS Tucker, “A Green Internet”, IEEE Lasers and Electro-Optics Society, 2008. Why Circuit Switching (CS) 3

Modern applications of circuit switching DAX L UK VPN Service Yahoo Data Centers Internet PAO DCP Yahoo Data Centers The Large hadron Collider network Five major yahoo! data centers and their connectivity A. Barczyk, World-wide Networking for LHC Data Processing, in National Fiber Optic Engineers Conference, OSA Technical Digest (Optical Society of America, 2012), paper NTulE 1 Y Chen, SJain, V.K. Adhikari, Z Zhang, and K. Xu, "a first look at inter-data center traffic characteristics via Yahoo datasets ,;in Proc. NFOCON,2011,pp.1620-1628

Modern applications of circuit switching • The Large Hadron Collider network • Five major Yahoo! data centers and their connectivity A. Barczyk, "World-wide Networking for LHC Data Processing," in National Fiber Optic Engineers Conference, OSA Technical Digest (Optical Society of America, 2012), paper NTu1E.1. Y. Chen, S. Jain, V.K. Adhikari, Z. Zhang, and K. Xu, "A first look at inter-data center traffic characteristics via Yahoo! datasets", ;in Proc. INFOCOM, 2011, pp.1620-1628. 4

Network in the future Circuit switching inside OXC: optical cross-connect core network Segregant Packets Packet 1 Core Network Aggregating Packets Packet 2 Packet 1 OXC Access Packet 4 Packet Network uter OXC Network Packet 1 Network Packet 2 Access Packet 3 Network

Network in the Future Circuit switching inside core network OXC: optical cross-connect 5

Blocking probability Overload situations in circuit switched networks -need to block calls Blocking probability Adverse impact on QoS Key performance measure for design and dimensioning

Blocking probability • Overload situations in circuit switched networks—need to block calls • Blocking probability • Adverse impact on QoS • Key performance measure for design and dimensioning 6

Alternate routing > Reduce blocking probability Primary Path If the shortest path is unavailable Origin Node the call can try other paths Destination Nor 0 · Edge-disjoint Problem Alternate 1) Alternate traffic usually use more pa resources than primary traffic 2)This inefficiency may lead to increase in blocking probability. Solution 1)Limit the number of choices of alternate paths 2) Add threshold to the alternate traffic certain capacity is exclusively reserved for primary traffic

➢ Reduce blocking probability If the shortest path is unavailable, the call can try other paths. • Edge-disjoint Problem: 1) Alternate traffic usually use more resources than primary traffic. 2) This inefficiency may lead to increase in blocking probability. Solution: 1) Limit the number of choices of alternate paths. 2) Add threshold to the alternate traffic￾certain capacity is exclusively reserved for primary traffic. Alternate Routing Origin Node Destination Node Primary Path Alternate path 7

Alternative routing Hierarchical Ranked into several tiers Non-hierarchical More flexible and efficient Accommodate sudden strong increase traffic of any od pair · Reduce cost Mutual overflow strong dependency Instability can be mitigated by trunk reservation

• Alternative routing – Hierarchical • Ranked into several tiers – Non-hierarchical • More flexible and efficient • Accommodate sudden strong increase traffic of any OD pair • Reduce cost • Mutual overflow • strong dependency • Instability – can be mitigated by trunk reservation 8

Approximation of circuit switched networks with non-hierarchical alternative routing Generally does not admit product form solution Rely on accurate approximation No robust methodology is available that captures the overflow-induced state dependency

Approximation of circuit switched networks with non-hierarchical alternative routing • Generally does not admit product form solution • Rely on accurate approximation • No robust methodology is available that captures the overflow-induced state dependency 9

Erlang fixed Point Approximation (EFPA >decoupling a given system into independent server groups >total traffic offered to any server follows a Poisson process all individual input streams all overflow attempts

Erlang Fixed Point Approximation (EFPA) ➢decoupling a given system into independent server groups ➢total traffic offered to any server follows a Poisson process ▪ all individual input streams ▪ all overflow attempts 10