Defining Networking Services for a Network Architecture supporting Media-oriented Service Composition Namgon Kim Networked Media Lab. GIST Project Discussion, Aug. 26, 2009.

Goal 미디어 서비스 합성에 적합한 네트워킹 서비스란 ? – 기존의 수동적인 ( 주어진 상황에 적응하는 ) 네트워킹 서비스를 벗어나서 능동적으로 요구되는 네트워킹을 확보할 수 있어야 함 – Flexible 한 서비스 합성을 지원하면서 동시에 QoS/QoE 를 위한 adaptability 를 제공하는 네트워킹이 되어야 함 Networked Media Lab. GIST2 미디어 서비스 합성에 적합한 네트워킹 서비스 미디어 서비스 합성을 잘하게 해주는 네트워킹 서비스 = 합성된 미디어 서비스가 사용자의 QoS 요구사항을 원하는 시간안에 만족시켜준다 미디어 서비스 합성에 적합한 네트워킹 서비스 미디어 서비스 합성을 잘하게 해주는 네트워킹 서비스 = 합성된 미디어 서비스가 사용자의 QoS 요구사항을 원하는 시간안에 만족시켜준다

Media-oriented service composition Today’s multimedia community is also on the move from monolithic multimedia applications to more flexible solutions The next generation of complex multimedia tasks in the multimedia domain is emerging and will require a strong support of service composition in order to build systems in a scalable, easy- programmable and flexible manner 3Networked Media Lab. GIST

Media-oriented service composition If multimedia service components are being composed into an advanced multimedia service, then they must satisfy – (a) functional dependency correctness, and – (b) meta-data QoS consistency correctness 4Networked Media Lab. GIST 미디어 서비스 합성에 적합한 네트워킹 서비스 합성된 미디어 서비스가 QoS Consistency 를 만족하는 서비스들 사이의 연결을 빠르게 찾을 수 있도록 해주는 네트워킹 서비스 미디어 서비스 합성에 적합한 네트워킹 서비스 합성된 미디어 서비스가 QoS Consistency 를 만족하는 서비스들 사이의 연결을 빠르게 찾을 수 있도록 해주는 네트워킹 서비스

Metrics for evaluating service composition – (a) time at which the service composition happens – (b) number of services participating in the service composition – (c) performance quality of service parameters – (d) content type that services process during the composition – (e) infrastructural support that the service composition needs for its instantiation and delivery ‘Performance quality’ represents the performance of each serivce parameterized via QoS parameters such as bandwidth, delay, jitter, information loss, and others. ‘Infrastructure support’ metric (service discovery, service instantiation, level of distribution, service routing) considers the underlying resource management system and networking services and protocols that are needed to execute the composed service instantiation, service delivery, and service adaptation in case of failures such as peer unavailability, peer overload and others 5Networked Media Lab. GIST

[Xu2002] Finding service paths in a Media Service Proxy Network A service path is a chain of media service proxies between a media source and a media client 6Networked Media Lab. GIST

[Gu2006] Distributed Multimedia Service Composition with Statistical QoS Assurances Networked Media Lab. GIST7 QSC (QoS-aware service composition) problem: To find the best mapping from the function graph to the best qualified ServFlow that satisfies the users multiconstrained QoS requirements and achieves best load balancing in the current multimedia service overlay

Limitations of Previous Works No consideration on how to construct service overlay network 기존의 수동적인 ( 주어진 상황에 적응하는 ) 네트워킹 서비스를 벗어나서 능동적으로 요구되는 네트워킹을 확보할 수 있어야 함 Networked Media Lab. GIST8

능동적으로 요구되는 네트워킹을 확보 [NGSON] 1.1 Scope and Purpose This White Paper describes a framework of Internet Protocol (IP)-based service overlay networks and specifies context-aware, (e.g., such as required Quality of Service (QoS) level, type of service such as realtime vs. data, nature of data stream such as I-frame vs. B-frame, and type of terminal such as TV monitor vs. personal digital assistant), dynamically adaptive (e.g., using locally derived information to discover, organize, and maintain traffic flows in the network within a local area network), and self-organizing networking capabilities (e.g., developing network structures based on the needs of the customers and the capabilities of existing network structures), including advanced service level routing and forwarding schemes, and that are independent of underlying transport networks. 주어진 네트워크 구조와 사용자의 요구사항에 기반하여 네트워크 구조를 만들어낸다 9Networked Media Lab. GIST

Virtual Network Networked Media Lab. GIST10 Virtual network is a collection of nodes connected by a set of virtual links forming virtual topology

Service Overlay Networks Networked Media Lab. GIST11 A SON purchases bandwidth with certain QoS guarantees from individual network domains via bilateral service level agreement (SLA) to build a logical end-to- end service delivery infrastructure on top of existing data transport networks.

Discussions Construct VN (or SON) satisfying resource requirements of requested media-oriented service composition How to construct a VN for media-oriented service composition – Hierarchical overlay according to resource capability? – Categorize media-oriented service composition requests? What is the assumption for the underlying network? – Network composed of general nodes? – Or network composed of special purpose nodes, like Networking-accelerated or Graphics-accelerated nodes? Networking Service = VN + networking service – Still, do we need to use the term ‘networking service’? Networked Media Lab. GIST12