Peer to Peer networks and Performance Hanoch Levy (hanoch at cs.tau.ac.il) Office: Kaplun 511 Office hours: by appointment 09.12.2018 H. Levy P2P+Performance

Course Information Lectures: Wed 9-12 Kaplun 319 Web site: http://www.cs.tau.ac.il/~hanoch/ And follow the link: Advanced topics in Computer-Networks – Peer-to-Peer Networks 09.12.2018 H. Levy P2P+Performance

Course Objective Study P2P networks Open the door for research in this area (Master/ Ph.D) Cover both: Theoretical background and advanced material 09.12.2018 H. Levy P2P+Performance

Course Approach Prerequisites: Course in computer / Equivalent / teacher approval Requirements: Most material is New (articles) Requires some analytic models Approach: Theoretical background (performance: elementary queueing theory) – frontal lectures by teacher. Recent material: (articles) – lectures by students 09.12.2018 H. Levy P2P+Performance

Course Structure and requirements First half of semester: Teacher lectures 2nd half of semester – student lectures. Each student gets one paper – and covers one paper in 45 minutes. 09.12.2018 H. Levy P2P+Performance

Course requirements First half (theoretical): In Class Exam (50-60% of grade) exam time: TBD – between 18.2.2011 and in-class exam. HW assignments 2nd Half: Give a good lecture. (40-50% of grade) Active participation will benefit a bonus Overflow students (if any): lecture replaced by special assignment by lecturer. 09.12.2018 H. Levy P2P+Performance

Course Information Supporting Books (theoretical part) Queueing Theory, L. Kleinrock, Vol I, Wiley (hard copy) Online books: Web site: http://web2.uwindsor.ca/math/hlynka/qonline.html (search “queueing hlynka) Introduction to Queueing Theory (2nd edition). Robert B. Cooper. 1981. 347 pp. This classic book is available on line through Robert Cooper's home page. The link to the book is: http://www.cse.fau.edu/~bob/publications/IntroToQueueingTheory_Cooper.pdf The solution manual (by Borge Tolt, 182 pages, 1981) is available online at http://www.cse.fau.edu/%7Ebob/publications/QueueingTheory_solns.pdf 09.12.2018 H. Levy P2P+Performance

Course Information Supporting Books (theoretical part – cont ) 3. Queueing Theory. Ivo Adan and Jacques Resing. 2001. 180 pp. 4. Queues: –A Course in Queueing Theor. Moshe Haviv. October 1, 2009. New and complete. 5. more… 09.12.2018 H. Levy P2P+Performance

Motivation Last 10-15 years: communications revolution Internet + Computer communications Is a key factor of the Information revolution Implications A drastic change of some aspects of life Revolution is affected by life Technology drives applications Applications drive technology 09.12.2018 H. Levy P2P+Performance

Motivation (cont) Applications / technology / research  rapidly change over time If want to stay in frontier: => Research material very dynamic => Course material very dynamic 09.12.2018 H. Levy P2P+Performance

Objectives Computer Networking course: Internet infra-structure 1 Introduction and Layering 2 Physical Layer, Data Link Layer, MAC Protocols 3 Hubs, Bridges, SwitchesData Link Layer 4 Switching UnitsSTP, Switching Fabric 5 Scheduling: Buffer Management Scheduling, WFQ example 6 Network Layer: RoutingRouting 7 Reliable Data TransferIP 8 End to End ProtocolsARQ 10 Flow Control, Congestion ControlTCP flow & congestion control 11 Network SecurityNetwork Sniffing (no slides) 12 DNS, HTTPTCP (state chart) 13 DDoS ALL – operations of network of networks. 09.12.2018 H. Levy P2P+Performance

Objectives (2) Advanced Material – network development following technology Peer to Peer (P2P): Bittorent, Skype Songs /movies / video-on-demand/video online 09.12.2018 H. Levy P2P+Performance

Internet Physical Infrastructure Residential access Cable Fiber DSL Wireless Backbone ISP ISP The Internet is a network of networks Each individually administrated network is called an Autonomous System (AS) Campus access, e.g., Ethernet Wireless 09.12.2018 H. Levy P2P+Performance 13

Data Networks Set of interconnected nodes exchange information sharing of the transmission circuits= "switching". many links allow more than one path between every 2 nodes. network must select an appropriate path for each required connection. 09.12.2018 H. Levy P2P+Performance

Real Network 09.12.2018 H. Levy P2P+Performance

Peer to Peer – what is it? “Historical” Internet : send data from A to K. Client-server model: A = server = data source K = client data consumer If C wants too – get from A (unicast or broadcast) 09.12.2018 H. Levy P2P+Performance

Peer to Peer – what is it A (source) sends to K. K (client) may become now a server. K sends to C (another client). 09.12.2018 H. Levy P2P+Performance

Peer to Peer – what the diff? K A Client (user) Server Private Commercial “Cost free” Costs “contributes” Charges Legal?? Legal obligations 09.12.2018 H. Levy P2P+Performance

Peer to Peer – what the diff? K A Huge number Small number Non reliable Reliable unplanned planned Huge traffic 80%!!!! 09.12.2018 H. Levy P2P+Performance

Peer to Peer – How important 0% of costs O(0)% of revenues 0% of planning  “Nothing” BUT: 80% of traffic  cannot disregard…  If you can’t beat them, join them… 09.12.2018 H. Levy P2P+Performance

Peer to Peer – Historical View Networks developed for 40+ years Internet – started developing late 70’s early 80’s Distributed, Semi Organized ATM – developed throughout the 90’s huge amount of money!!! Very well organized network “failed” P2P – started in the 00’s VERY unorganized 80% of traffic (though SMALL % of money) 09.12.2018 H. Levy P2P+Performance

Theory Many network models – based on stochastic modeling Queueing systems Stochastic processes P2P models – included Objective: study basic stochastic / queueing models Elementary Queueing theory 09.12.2018 H. Levy P2P+Performance