Service Control Functions Research Articles

SIMULATION MODELING OF ADAPTIVE ROUTING UNDER EXTERNAL DESTROYING EFFECTS IN NGN NETWORKS

Modern subscribers of infocommunication services require a wide class of different services and applications, implying a wide variety of protocols, technologies and transmission rates. Networks are overloaded in the prevailing situation in the market of infocommunication services: they are overflowing with numerous customer interfaces, network layers and are controlled by too many control systems. High operating costs are pushing operators to look for solutions that simplify the operation, while maintaining the possibility of creating new services and ensuring the stability of existing sources of income from the provision of communication services. The NGN concept is the concept of building next-generation communication networks (Next-generation network), providing an unlimited set of services with flexible settings for their management, personalization, creation of new services through the unification of network solutions. Multiservice network is a communication network that is built in accordance with the NGN concept and provides an unlimited set of infocommunication services (VoIP, Internet, VPN, IPTV, VoD, etc.). An NGN is a packet-switched network suitable for the provision of telecommunication services and for the use of multiple broadband transport technologies with QoS enabled, in which the service-related functions are independent of the applied transport technologies. The main feature of NGN networks is the differentiation between services and transport technologies. This allows to view the network as a logically divided entity. Each layer of the network can evolve independently without affecting other layers. Inter-layer communication is based on open interfaces. The logical separation principle allows the provision of both existing and innovative services access technologies regardless of the used transport. The basic principle of the NGN concept is to separate from each other transfer and switch functions, call control functions and service control functions.

A Prototype Virtual Network Embedding System using OpenStack

Network virtualization enables us to make efficient use of resources in a physical network by embedding multiple virtual networks in the physical network. In this paper, we develop a prototype of a virtual network embedding system. Our system consists of OpenStack, which is an open source cloud service platform, and shell scripts. Because OpenStack does not provide a quality of service control function, we realize bandwidth reservation for virtual links by making use of the ingress policing function of Open vSwitch, which is a virtual switch used in OpenStack. The shell scripts in our system automatically construct the required virtual network on the physical network using the OpenStack command-line interface, and they reserve bandwidth for virtual links using the Open vSwitch command. Experimental evaluation confirms that our system constructs the requested virtual network and appropriately allocates node and link resources to it.

Scalable software architecture for distributed MMORPG traffic generation based on integration of UrBBaN-Gen and IMUNES

We present a scalable software architecture for distributed traffic generation capable of producing Massively Multiplayer Online Role-Playing Game (MMORPG) packet flows in a statistically accurate manner for thousands of concurrent players. The main challenge, to achieve truly massive scale traffic generation, has been achieved by introducing kernel based virtualization, pioneered by the network simulator/emulator IMUNES, into the User Behaviour Based Network Traffic Generation (UrBBan-Gen, introduced in our earlier work). The UrBBan-Gen software architecture consists of four modules: Service repository, Control function and user interface, Behaviour process, and Traffic generation process. IMUNES has been integratedinto the virtualization part of the Traffic generation process,which has resulted in two improvements: 1) increasing thenumber of generated packet flows while accurately replicating the required statistical properties, and, 2) introducing the ability to run various network scenarios in simulated, as well as real networks, under realistic traffic loads. With respect to the traffic generation capabilities of the previous version of UrBBan-Gen, which was based on Linux containers, the IMUNES based solution demonstrates higher scalability, lower packet loss rates, and lower CPU load for both the UDP traffic at high packet rate and “thin” TCP traffic flows typical for MMORPGs.

Load balancing mechanism of service control server cluster in IMS-based IPTV

IMS-based IPTV not only requires higher performance of Service Control Function ( SCF) server, but also brings many restrictions to the traditional load balancing technologies due to a Session Initiation Protocol ( SIP) with double integrity requirements of transaction and dialog. Combining service trigger mechanism in IP Multimedia Subsystem ( IMS) and the session statistical characteristic of the IPTV services, a multi-level load balancing mechanism with the features of service differentiation among clusters and server-load awareness within every cluster was discussed to solve the performance bottleneck in IPTV SCF, and a method differentiating SIP transaction priorities and a lightly random scheduling algorithm based on a dynamic weight were proposed. Finally, the technological feasibility was verified in IPTV prototype, and the detailed solution was depicted.

Objective Speech Quality Assessment Based on Payload Discrimination of Lost Packets for Cellular Phones in NGN Environment

A feature of services provided in a Next Generation Network (NGN) is that the end-to-end quality is guaranteed. This is quite a challenging issue, given the considerable fluctuation in network conditions within a Fixed Mobile Convergence (FMC) network. Therefore, a novel approach, whereby a network node and a mobile terminal such as a cellular phone cooperate with each other to control service quality is essential. In order to achieve such cooperation, the mobile terminal needs to become more intelligent so it can estimate the service quality, including the user's perceptual quality, and notify the measurement result to the network node. Subsequently, the network node implements some kind of service control function, such as a resource and admission control function, based on the notification from the mobile terminal. In this paper, the role of the mobile terminal in such collaborative system is focused on. As a part of a QoS/QoE measurement system, we describe an objective speech quality assessment with payload discrimination of lost packets to measure the user's perceptual quality of VoIP. The proposed assessment is so simple that it can be implemented on a cellular phone. We therefore did this as part of the QoS/QoE measurement system. By using the implemented system, we can measure the user's perceptual quality of VoIP as well as the network QoS metrics, in terms of criteria such as packet loss rate, jitter and burstiness in real time.

P2P IPTV 서비스를 위한 세션 제어 메카니즘

본 논문은 P2P(Peer to Peer) IPTV(Internet Protocol Television) 서비스를 위한 세션 제어 모델을 제시하고, 제시된 모델에 근거한 IPTV 세션 제어 절차에 대해 논한다. 별도의 전용망에 의해 관련 트래픽이 처리되는 공중 IPTV(Public IPTV)와 달리 P2P IPTV 트래픽은 인터넷 접속 트래픽의 일부로 망에 의해 처리되어야 한다. 따라서 P2P IPTV 세션 제어는 IPTV를 구성하는 TPS(Triple Play Service) 트래픽을 기존 인터넷 트래픽과 분리하여 적절하게 제어할 수 있어야 하고, 분리된 TPS 트래픽을 차별화하여 처리하는 QoS(Quality of Service) 제어 기능을 포함해야 한다. 뿐만 아니라 P2P IPTV 세션 제어는 불특정 다수에 의한 비디오 전송을 효과적으로 지원하기 위한 적절한 멀티캐스트 제어 기능을 반드시 포함해야 한다. 본 논문의 P2P IPTV 세션 제어 모델은 상호 연동성(Inter-operability)이 보장되는 P2P IPTV 플랫폼의 조기 구축에 기여할 수 있도록 표준 SIP(Session Initiation Protocol), IGMP(Internet Group Management Protocol), 그리고 COPS(Common Open Policy Service) 프로토콜에 근거하여 설계되었다. This paper proposes a session control model for the P2P(Peer to Peer) IPTV(Internet Protocol Television) services and presents the IPTV session control procedures based on the proposed model. Since, while public IPTV traffic is usually processed via a separate network, P2P IPTV traffic is processed together with the conventional Internet access traffic, the P2P IPTV control mechanism needs to provide multi-stream processing for the constituent TPS(Triple Play Service) traffic and corresponding QoS(Quality of Service) control functions. Besides, P2P IPTV session control mechanism should provide appropriate multicast control functions in order to support effective transmission of video traffic generated by personal IPTV broadcasters. The P2P IPTV session control model proposed in this paper is designed to be based on the standard SIP(Session Initiation Protocol), IGMP(Internet Group Management Protocol), and COPS(Common Open Policy Service) protocol so that it can contribute to the easy and prompt deployment of inter-operable P2P IPTV platform.

Provision of unified IN functionality in the context of IMS

The IP Multimedia Subsystem (IMS) represents an attempt for networks convergence, allowing users of rich-content applications to communicate through any access network type. In the near future, IMS is expected to give operators and content providers the flexibility to exploit a multitude of new communication applications in a harmonized communication environment of heterogeneous IP networks. However, despite its merits, the standardization process of IMS networks is lagging behind, leaving harmonization issues of services provisioning, open. In this effort, main hindering factor is the existence of similar implementations customized per network technology. Particularly in what concerns the Intelligent Network (IN) services, these are provided in mobile networks by CAMEL (Customised Applications for Mobile networks Enhanced Logic) and in fixed networks by INAP (IN Application Part). With regard to this problem, the present work introduces a method for integrating into the context of IMS communications all types of IN logic that nowadays are available only in legacy networks. The key element of this method is a service interrogation logic, called IN-OAG (IN-Open Architecture Gateway), which can be integrated on the P-CSCF (Proxy-Call Service Control Function) component of IMS, as an enhancement for supporting IN interoperability. IN-OAG is dedicated to implementing interoperability between the core IMS and mobile, wireless or fixed networks. The functionality of the proposed architecture is shown through several example scenarios.

Using TINA concepts for IN evolution

This article proposes solutions that use TINA concepts for the future evolution of IN. It focuses on the specific need to provide a software architecture for the IN service control function which controls the transport network through INAP. After giving an overview of the TINA architecture, the article examines how it can be applied to IN. Several aspects are considered, such as architectural modeling, application of software technology and methodology, and definition of sets of standard open interfaces. The article concludes with a view on related activities in industrial fora.

An architecture for managing virtual circuit and virtual path services in ATM networks

ATM networks rely on the Virtual Circuit (VC) and Virtual Path (VP) concepts to provide unicast connection-oriented services with Quality of Service (QoS) guarantees. This paper presents a model for managing the configuration and performance of the VC and VP services in these networks. The model consists of a connection management architecture that provides the services and is instrumented for network management purposes, and a network management architecture that uses the OSI management model to provide access to the appropriate service monitoring and control functions. The network management architecture proposes complete managed object definitions that achieve a variety of monitoring and control objectives: service configuration, service performance at the call and cell level, and service control. The latter includes the capability to establish VPs and control their allocated networking capacity and also control parameters of the signaling system that affect the performance of the VC service. The architecture was implemented in its entirety on the Xunet ATM testbed, and several experiments were conducted to illustrate the trade-off between the throughput of the VC service and the allocation of capacity to VPs. The experiments further demonstrated that the signaling system can create throughput bottlenecks in the absence of VPs in the network, and therefore, the network operator can increase performance by controlling the VP distribution.

Towards integration of service and network management in TINA

The Telecommunications Information Networking Architecture (TINA) defines a framework to support the rapid and flexible deployment and management of a wide range of multi-media, multi-party services in a multi-vendor telecommunications environment. The TINA approach applies opendistributed processing (ODP) and object-oriented design techniques to specify the control and management of the telecommunications services and infrastructure. Management in TINA is applied to the different components of the architecture, services and resources, and to thedistributed processingenvironment (DPE) that provides distribution transparencies and communication capabilities among TINA components. Management in TINA is based on TMN and extended with ODP concepts, as TINA is not concerned with just network management, but also systems management. TINA management architecture addresses aspects of distribution, interoperability, dynamic manager/managed roles, and integration with service control functions. TINA service management concerns different activities of the service life-cycle, from four main aspects: access session management, service session management, user session management and communication session management. The TINA network resource model supports requirements from both network management activities and service connectivity needs.