TTM 5 Networked Services and Multimedia Systems advanced

TTM 5 Networked Services and Multimedia Systems, advanced Professor Peter Herrmann/ Postdoc Hien Nam Le Dept. Telematics (ITEM) University of Science and Technology (NTNU) hiennam@item. ntnu. no Rm A 277 1

Introduction • Objective – This course shall give in-depth knowledge of principles, frameworks, and languages used for providing multimedia services over networks. • Contents – SOA & Multimedia Systems – Multimedia tools and frameworks for providing multimedia services • • 2 Framework and architecture Service discovery and delivery Deployment and management Other issues: mobility, location-based, transaction services

Introduction • Recommended background – – – Communication - Services and Networks (TTM 4100) Access and Transport Networks (TTM 4105) Network Intelligence and Mobility (TTM 4130) Internet network architecture or equivalent (TTM 4150). Service and Resource Management (TTM 4128) • Assessment – Oral or writing examinations – Date: 03 Dec 2007 • Questions/requests – Email or walk-in rm A 277 3

Schedule • 7 two-hours seminars Week Date 40 41 10. 07 42 17. 10. 07 43 24. 10. 07 44 31. 10. 07 45 07. 11. 07 46 14. 11. 07 47 4 03. 10. 07 21. 11. 07 Topics Introduction & review Guest lecture: Open Mobile Services Lecturer: Prof. Do, van Thanh

Topics • Introduction, review and background on multimedia systems and network services – Multimedia systems – Service-oriented architecture • Framework and architecture for developing multimedia services • Discovery and delivery of multimedia services • Deployment and management of multimedia services • Other issues – Location-based services, mobility, transaction services 5

An overview picture • Example – Develop a movie information service • Requirements 6

An overview picture Live Free or Die Hard John Mc. Clane takes on an Internet-based terrorist organization who is … Text Photos Multimedia System • Storage • Presentation • Search and retrieval 7 Video clip

An overview picture Development Tools, framework, architecture Multimedia System/ Application Interactions Clients 8

An overview picture Multimedia System/ Services Application Service-oriented Computing/ Service-oriented Architecture Service provider Services Interactions Publishing Service registry Clients Service Clients 9 Finding Binding Service clients

Course materials • Introduction, review and background – G. Coulouris, J. Dollimore, T. Kindberg: Distributed Systems: Concepts and Design, Chapter 15: Distributed Multimedia System – Mike P. Papazoglou: Service-Oriented Computing: Concepts, Characteristics and Directions. WISE 2003: 3 -12 – Michael N. Huhns, Munindar P. Singh: Service-Oriented Computing: Key Concepts and Principles. IEEE Internet Computing 9(1): 75 -81 (2005) – Jilles van Gurp, Anssi Karhinen, Jan Bosch: Mobile Service Oriented Architectures (MOSOA) • Additional reading – Donald F. Ferguson, Marcia L. Stockton: Service-oriented architecture: Programming model and product architecture. IBM Systems Journal 44(4): 753 -780 (2005) – Mark Little: Transactions and Web services. Commun. ACM 10(43) (2003) – Gerald C. Gannod and Janet E. Burge and Susan D. Urban: Issues in the Design of Flexible and Dynamic Service-Oriented Systems. SDSOA '07: Proceedings of the International Workshop on Systems Development in SOA Environments 10

Course materials • Framework and architecture – Jia Zhang, Jen-Yao Chung: An open framework supporting multimedia web services. Multimedia Tools Appl. 30(2): 149 -164 (2006) – Vassilios N. Koukoulidis, Mehul Shah: The IP multimedia domain: service architecture for the delivery of voice, data, and next generation multimedia applications. Multimedia Tools Appl. 28(1 -2): 203 -220 (2006) – Ahmet Uyar, Wenjun Wu, Hasan Bulut, Geoffrey Fox: Service-Oriented Architecture for Building a Scalable Videoconferencing System, in book "Service-Oriented Architecture - Concepts & Cases" published by Institute of Chartered Financial Analysts of India (ICFAI) University – Thanh, d. V. ; Jorstad, I. ; Dustdar, S. : Mobile Multimedia Collaborative Services. (2006) • Additional reading 11 – Jia Zhang, Jen-Yao Chung: A SOAP-Oriented Component-Based Framework Supporting Device-Independent Multimedia Web Services. ISMSE 2002: 40 -47

Course materials • Discovery and delivery – Yi Cui, Klara Nahrstedt, Dongyan Xu: Seamless User-Level Handoff in Ubiquitous Multimedia Service Delivery. Multimedia Tools Appl. 22(2): 137 -170 (2004) – Conor Muldoon, Gregory M. P. O'Hare, Rem W. Collier, Donnacha Phelan, Robin Strahan: Intelligent Delivery of Multimedia Content in a Device Aware Ubiquitous Environment. Multimedia Information Systems 2005: 131 -145 – Ricky Robinson, Jadwiga Indulska: A Context-Sensitive Service Discovery Protocol for Mobile Computing Environments. ICMB 2005: 565 -572 – Zhou Wang and Hend Koubaa: Discovering Multimedia Services and Contents in Mobile Environments. Handbook of Research on Mobile Multimedia 12

Course materials • Deploy and Management – Chih-Cheng Lo, Wen-Shyen E. Chen: Deploy Multimedia-on. Demand Services over ADSL Networks. IEEE Pacific Rim Conference on Multimedia 2002: 295 -302 – Klara Nahrstedt, Wolf-Tilo Balke: A taxonomy for multimedia service composition. ACM Multimedia 2004: 88 -95 13

Course materials • Other issues – Stefan Tai, Thomas A. Mikalsen, Eric Wohlstadter, Nirmit Desai, Isabelle Rouvellou: Transaction policies for serviceoriented computing. Data Knowl. Eng. 51(1): 59 -79 (2004) – Minsoo Lee, Gwanyeon Kim, Sehyun Park, Sungik Jun, Jaehoon Nah, Ohyoung Song: Efficient 3 G/WLAN Interworking Techniques for Seamless Roaming Services with Location-Aware Authentication. NETWORKING 2005: 370381 – Zhiwen Yu and Daqing Zhang: Middleware Support for Context-Aware Ubiquitous Multimedia Services. Handbook of Research on Mobile Multimedia. 14

Multimedia Services over Networks Review/background Framework/ Architecture Service provider Delivery Bind Publish Deployment/ Management Multimedia system Service registry Find/discovery Service client Issues: Transactions/mobility/locations 15

Distributed Multimedia Systems Chapter 15 – CDK book Slides 16

A distributed multimedia system Figure 15. 1 Video camera and mike Local network Wide area gateway. Video server Digital TV/radio server • Applications: 17 – non-interactive: net radio and TV, video-on-demand, e-learning, . . . – interactive: voice &video conference, interactive TV, tele-medicine, multi-user games, live music, . . .

Learning objectives • To understand the nature of multimedia data and the scheduling and resource issues associated with it. • To become familiar with the components and design of distributed multimedia applications. • To understand the nature of quality of service and the system support that it requires. • To explore the design of a state-of-the-art, scalable video file service; illustrating a radically novel design approach for quality of service. 18

Multimedia in a mobile environment • Applications: – Emergency response systems, mobile commerce, phone service, entertainment, games, . . . 19

Characteristics of multimedia applications • Large quantities of continuous data • Timely and smooth delivery is critical – deadlines – throughput and response time guarantees • Interactive MM applications require low round-trip delays • Need to co-exist with other applications – must not hog resources • Reconfiguration is a common occurrence – varying resource requirements • Resources required: – – – 20 Processor cycles in workstations and servers Network bandwidth (+ latency) Dedicated memory Disk bandwidth (for stored media) At the right time and in the right quantities

Application requirements • Network phone and audio conferencing – relatively low bandwidth (~ 64 Kbits/sec), but delay times must be short ( < 250 ms round-trip) • Video on demand services – High bandwidth (~ 10 Mbits/s), critical deadlines, latency not critical • Simple video conference – Many high-bandwidth streams to each node (~1. 5 Mbits/s each), high bandwidth, low latency ( < 100 ms round-trip), synchronised states. • Music rehearsal and performance facility – high bandwidth (~1. 4 Mbits/s), very low latency (< 100 ms round trip), highly synchronised media (sound and video < 50 ms). 21

System support issues and requirements • Scheduling and resource allocation in most current OS’s divides the resources equally amongst all comers (processes) – no limit on load – can’t guarantee throughput or response time • MM and other time-critical applications require resource allocation and scheduling to meet deadlines – Quality of Service (Qo. S) management • Admission control: controls demand • Qo. S negotiation: enables applications to negotiate admission and reconfigurations • Resource management: guarantees availability of resources for admitted applications – real-time processor and other resource scheduling 22

Characteristics of typical multimedia streams Figure 15. 3 Data rate (approximate) Sample or frame size frequency Telephone speech CD-quality sound Standard TV video (uncompressed) 64 kbps 1. 4 Mbps 120 Mbps 8 bits 8000/sec 16 bits 44, 000/sec up to 640 480 x 24/sec pixels 16 bits x Standard TV video (MPEG-1 compressed) 1. 5 Mbps HDTV video (uncompressed) HDTV video MPEG-2 compressed) 23 variable 24/sec 1000– 3000 Mbpsup to 1920 x 1080 24– 60/sec pixels 24 bits x 10– 30 Mbps variable 24– 60/sec

Typical infrastructure components for multimedia applications Figures 15. 4 & 15. 5 PC/workstation Window system H G Codec PC/workstation : multimedia stream White boxes represent media processing components, many of which are implemented in software, including: codec: coding/decoding filter mixer: sound-mixing component Camera A Microphones B Screen K Codec L Mixer C D Codec Network connections M Video file system Video store Window system Component Bandwidth Latency Loss rate Resources required Camera Out: 10 frames/sec, raw video 640 x 480 x 16 bits Zero A Codec In: Out: 10 frames/sec, raw video Interactive Low MPEG-1 stream L Network In/Out: Audio 44 kbps connection 10 ms CPU each 100 ms; 10 Mbytes RAM • This application involves multiple concurrent processes in the B Mixer In: 2 44 kbps audio Interactive Very low 1 ms CPU each 100 ms; PCs Out: 1 44 kbps audio 1 Mbytes RAM Window In: various Interactive Low 5 ms CPU each 100 ms; • H Other applications may also be running concurrently on the same system Out: 50 frame/sec framebuffer 5 Mbytes RAM computers K Network In/Out: MPEG-1 stream, approx. Interactive Low 1. 5 Mbps, low-loss connection 1. 5 Mbps stream protocol • They all share processing and network resources 24 Interactive Very low 44 kbps, very low-loss stream protocol

The Qo. S manager’s task Figure 15. 6 25

Qo. S Parameters Bandwidth – rate of flow of multimedia data Latency – time required for the end-to-end transmission of a single data element Jitter • variation in latency : – d. L/dt Loss rate – the proportion of data elements that can be dropped or delivered late 26

Admission control delivers a contract to the application guaranteeing: For each network connection: For each computer: wbandwidth wlatency • cpu time, available at specific intervals For disks, etc. : • memory wbandwifth wlatency Before admission, it must assess resource requirements and reserve them for the application – Flow specs provide some information for admission control, but not all - assessment procedures are needed – there is an optimisation problem: • clients don't use all of the resources that they requested • flow specs may permit a range of qualities – Admission controller must negotiate with applications to produce an acceptable result 27

Resource management • Scheduling of resources to meet the existing guarantees: e. g. for each computer: wcpu time, available at specific intervals wmemory Fair scheduling allows all processes some portion of the resources based on fairness: • E. g. round-robin scheduling (equal turns), fair queuing (keep queue lengths equal) • not appropriate for real-time MM because there are deadlines for the delivery of data Real-time scheduling traditionally used in special OS for system control applications - e. g. avionics. RT schedulers must ensure that tasks are completed by a scheduled time. Real-time MM requires real-time scheduling with very frequent deadlines. Suitable types of scheduling are: Earliest deadline first (EDF) Rate-monotonic 28

Scaling and filtering Figure 15. 9 Source Targets High bandwidth Medium bandwidth Low bandwidth • Scaling reduces flow rate at source – temporal: skip frames or audio samples – spatial: reduce frame size or audio sample quality • Filtering reduces flow at intermediate points 29 – RSVP is a Qo. S negotiation protocol that negotiates the rate at each intermediate node, working from targets to the source.

Tiger design goals (self-study) • • • Video on demand for a large number of users Quality of service Scalable and distributed Low cost hardware Fault tolerant Tiger Clients Network 30

Youtube www. youtube. com • Supports the delivery of over 100 million videos per day – That is 4. 167. 000 per hour, 69. 000 per minut, 1. 150 per second • The team: 2 sysadmins, 2 scalability software architects 2 feature developers, 2 network engineers, 1 DBA. • What's essential to your service and prioritize your resources and efforts around those priorities • Keep it simple! Simplicity allows you to re-architect more quickly so you can respond to problems • http: //highscalability. com/youtube-architecture 31

What is a Multimedia System? • A system that involves: – – – Generation: production/authoring tools Representation: compression and formats Storage: file system design Transmission: networking issues, Qo. S Search and retrieval: database management Delivery: service design, Qo. S of multimedia information 32

Service-oriented Architecture • What is a service? – A Windows Service? • RPC Locator, Event. Log, DHCP Client, – Software Service? • Distribution Service, Alert Service • Security Service, Log Service – Business Service? • Common Operational Picture, Navigation • Accounts Receivable, Customers • A service is a unit of work done by a service provider to achieve desired end results for a service consumer. 33

Papers • Mike P. Papazoglou: Service-Oriented Computing: Concepts, Characteristics and Directions. WISE 2003: 3 -12 – Michael N. Huhns, Munindar P. Singh: Service-Oriented Computing: Key Concepts and Principles. IEEE Internet Computing 9(1): 75 -81 (2005) • Jilles van Gurp, Anssi Karhinen, Jan Bosch: Mobile Service Oriented Architectures (MOSOA) • Additional reading – Donald F. Ferguson, Marcia L. Stockton: Service-oriented architecture: Programming model and product architecture. IBM Systems Journal 44(4): 753 -780 (2005) – Mark Little: Transactions and Web services. Commun. ACM 10(43) (2003) – Gerald C. Gannod and Janet E. Burge and Susan D. Urban: Issues in the Design of Flexible and Dynamic Service-Oriented Systems. SDSOA '07: Proceedings of the International Workshop on Systems Development in SOA Environments 34

Services… • Technology neutral – Invocation mechanisms (protocols, descriptions, discovery) should comply with accepted standard • Loosely coupled – Must not require knowledge at the service side • Support location transparency – Service can be discovered and invoked by clients irrespective of their locations • Simple and composite services 35

Loosely coupling • Outlet plug adapters • Standard? ? ? 36

SOA vs. Objects/components • Services represent complete business functions • Re-used • CD-player example – CD – Players – Object oriented • CD+Player • Other issues – Stateless service more scalable & reliable – Stateful service more efficiency – Itempotent request 37

Service-oriented Architecture • SOA is an architecture style whose goal is to achieve loose coupling among interacting software agents – Consumers and Providers are agents • Minimum difference of plug adaptors • We need – A small & simple interface to all participating agents – Descriptive messages constrained 38

How can we identify an SOA? • Descriptive message – Order service, not how to “cook” the service • Understandable protocols/messages – Look at the menu, do not describe the “food” • Extensibility – vs. restrictions • Discovery service 39

An overview picture • Example – Develop a movie information service • Requirements 40

Services oriented architecture - basic Service provider Publish Service registry 41 Bind Find/discovery Service client

Service interfaces and implementation 42

Extened SOA • Basic SOA does not address – Management – Service orchestration – Transaction, security, … • Extended SOA 43

Extened SOA 44

Web services Internet protocols: HTTP, FTP XML messages vs. SOA definition? Service provider WSDL Publish UDDI Service registry 45 Bind SOAP Find/discovery Service client

Web services 46