1 CSE 5346 – Networks II: High Performance Networks

2 Introduction Performance and Quality of Service

Introduction 3 Course Foundation Assumptions (pre-requisites) Good understanding of packet-switched networking concepts and principles of operation Good understanding of packet-switched networking concepts and principles of operation Good understanding of Internet protocols and architectures (e.g., IP protocol stack) Good understanding of Internet protocols and architectures (e.g., IP protocol stack) Solid foundation in computer operating systems fundamentals Solid foundation in computer operating systems fundamentals Ability to learn simple programming languages (such as ns/2 tcl, C/C++) Ability to learn simple programming languages (such as ns/2 tcl, C/C++) Ability to perform independent research, analyze findings and document results Ability to perform independent research, analyze findings and document results

Introduction 4 What will we cover? Networking Introduction/Review Networking Introduction/Review –Today… setting the stage Frame Relay, ATM & High Speed LANs Frame Relay, ATM & High Speed LANs Performance Modeling and Estimation Performance Modeling and Estimation Congestion, Network Traffic Analysis/Management and Routing Congestion, Network Traffic Analysis/Management and Routing Quality of Service Quality of Service Compression Standards and Practice Compression Standards and Practice Advanced Topics (time permitting): VoIP, Mobile IP, Mobile Agents Advanced Topics (time permitting): VoIP, Mobile IP, Mobile Agents Some Review New Content

Introduction 5 How will we cover it? Classroom lectures Classroom lectures Quizzes and exams Quizzes and exams Incremental modeling and simulation project using ns/2 Incremental modeling and simulation project using ns/2 Self-study research, and simulation reports by students Self-study research, and simulation reports by students Study and student presentations on relevant papers & RFCs Study and student presentations on relevant papers & RFCs

6 Chapter 1 - Introduction An Overview of Networking - the Need for Speed and Quality of Service

Introduction 7 The Evolution of Networks & Internetworking ARPANET to Internet ARPANET to Internet –Initial packet switched technology –DOD ARPA funded –4 nodes in 50kbps –TELNET & FTP: first standard network applications –1972 “Killer App”: ! Internet to WWW –Cerf & Kahn – TCP, 1974 –ARPANET: NCP to TCP, –NSF backbone –ARPANET shut down, 1990 –Mosaic: 1992 –U.S. Government Internet funding terminated in 1995

Introduction 8 Growth of the Internet As of January 2005 … > 300 million “computers” in 209 countries

Introduction 9 What is an/the Internet? connected computing devices: hosts, end- systems connected computing devices: hosts, end- systems –PC’s, workstations, servers –PDA’s, phones, toasters, cars running network applications communication links communication links –fiber, copper, radio, satellite routers/switches: forward packets (chunks) of data thru network routers/switches: forward packets (chunks) of data thru network router workstation server mobile local ISP companynetwork regional ISP

Introduction 10 The Need for Speed! Scale Scale –growing number of hosts -> growing demands on bandwidth –new technologies result in new paradigms for device and connection types e.g. ?? e.g. ?? Application Application –demand for large to huge file transfers –increasing critical nature of Internet use –demand for “real- time” performance characteristics –demand for guarantees of service levels e.g. ?? e.g. ?? User Expectations! User Expectations!

Introduction 11 High-Speed Networks: IDN to ATM IDN (Integrated Digital Network) IDN (Integrated Digital Network) –early ’60s, answer to growth of digital, computer-controlled, circuit-switched networking –WE 4ESS introduced in 1976, 1 st large scale commercial time-division switch ISDN (Integrated Services Digital Network) ISDN (Integrated Services Digital Network) –integrated voice and data on the same digital transmission links/exchanges –small incremental cost for data over existing digital voice network

Introduction 12 High-Speed Networks: IDN to ATM Frame Relay Frame Relay –popularized standard (c. 1988) for packet switching over ISDN –most widely deployed WAN technology in use today B-ISDN (Broadband ISDN) B-ISDN (Broadband ISDN) –c. 1988: emerging demand for broadband services –new high-speed technologies available –emerging bandwidth hungry applications

Introduction 13 High-Speed Networks: IDN to ATM ATM (Asynchronous Transfer Mode) ATM (Asynchronous Transfer Mode) –early ’90s outgrowth of emerging need for high- speed switching over B-ISDN WAN –rapidly evolved as high-speed packet switching technology of its own accord –primary deployment today is: public network infrastructure LAN backbone private network, VPN WAN –services not widely deployed/available until late-’90s.

Introduction 14 High-Speed Networks: ATM Backbone Example

Introduction 15 High-Speed Networks: LANs High-speed LANs High-speed LANs –driven by explosive growth in speed and computing power of PCs in 1990s –emergence of client-server computing architecture –use of centralized server farms –emergence of “power workgroups” and workgroup applications –need for local high-speed LAN backbones

Introduction 16 IP-based Internets (aka TCP/IP networks) Internetworking: the dominant paradigm of computer networking Evolution - key internetworking technologies: packet switching packet switching TCP/IP TCP/IP –TCP: reliable end-to-end transport –IP: internet routing and delivery dynamic routing, load balancing dynamic routing, load balancing high speed Ethernet LANs high speed Ethernet LANs

Introduction 17 Advancements in TCP/IP Networks Recent advancements driven by the need to support multimedia and real-time traffic Recent advancements driven by the need to support multimedia and real-time traffic Emergence of Internet’s Integrated Services Architecture (ISA, or IntServ) and Differentiated Service (DS, or DiffServ) Emergence of Internet’s Integrated Services Architecture (ISA, or IntServ) and Differentiated Service (DS, or DiffServ)  New QoS Architecture/Framework is driving protocol changes: –IPv6 – introduces new features for QoS –RSVP – Resource ReSerVation Protocol –RTP – Real Time Protocol –Multicast routing (IGMP, MOSPF, PIM) –Multi-Protocol Label Switching (MPLS)

Introduction 18 The Need for Improved (better) Levels of Service Internet Best- Effort Service Internet Best- Effort Service –all packets treated equally –designed for elastic traffic –no guarantees of bandwidth or throughput –no guarantees of delay –no guarantee of jitter (delay variation) Applications Applications –often create inelastic traffic –often sensitive to delay –often sensitive to jitter –often critical in nature –generate elastic traffic as well User Requirements! User Requirements!

Introduction 19 Delay Sensitivity & Criticality

Introduction 20 Delays in Packet Switched (e.g. IP) Networks End-to-end delay (simplified) = End-to-end delay (simplified) = (d prop + d trans + d queue + d proc ) x Q (d prop + d trans + d queue + d proc ) x Q B A Where:  Propagation delay (d prop )  Transmission delay (d trans )  Queuing delay (d queue )  Processing delay (d proc )  Number of links (Q)

Introduction 21 So what’s the problem? What makes this so hard? (I.e., what are we going to focus on in this course.)

Introduction 22 Delays in Packet Switched (e.g. IP) Networks End-to-end delay (simplified) = End-to-end delay (simplified) = –(d prop + d trans + d queue + d proc ) … on each link More later B A Where:  Propagation delay (d prop ) = d/s  Transmission delay (d trans ) = L/R ?  Queuing delay (d queue ) = ? ?  Processing delay (d proc ) = ? ?  Number of links (Q) = ?