Service Interaction Problem Research Articles

Detecting OAM&P design defects using a feature interaction approach

In the telecommunications service engineering world, the feature interaction (FI) problem is defined as the situation in which running services at the same time undesirably alters their behaviour. It is also known as the service interaction problem. FIs may occur between various types of services, ranging from signalling protocol features to value-added end-user services. The problem has been widely investigated for those types of services. However, sufficient attention has not been paid to operation, administration, management and provisioning (OAM&P) features like creating a new customer account or registering a new gateway as part of the network. The present paper addresses the detection of OAM&P FIs in Internet telephony architectures. The solution consists in an adapted version of a known FI detection method. A simple feature modelling language and an FI detection procedure are proposed. A validation with a case study is also reported. Copyright © 2011 John Wiley & Sons, Ltd.

A pragmatic approach to service interaction filtering between call control services

Triggered by the deregulation of the telecommunications market, it is expected that the number of services deployed in the telecommunications network will increase dramatically in the near future. It is expected that these services will be interworking. However, as widely reported, interworking services will be subject to the service interaction problem. It is essential to cope with the problem in a developing multi service provider environment as it may substantially delay service deployment and hence form a serious obstacle to rapid service provisioning. In order to cope with the increasing number of services deployed in the network, previous work suggested the application of filtering approaches. This paper suggests such a technique. It is pragmatic in nature and does not require detailed service knowledge. Furthermore, it is shown how the approach can be incorporated into an overall comprehensive service interaction management process. Even though the approach is applied to call control aspects only, it could be extended to cover other areas.

Application of formal verification and behaviour abstraction to the service interaction problem in intelligent networks

One of the major drawbacks for the use of formal methods is the excessive size of the state-spaces representing behaviours of industrial-sized specifications of concrete systems. Existing verification algorithms simply are often not applicable to the large systems of practical relevance. One can improve the applicability of verification methods by orders of magnitude by ignoring parts of a behaviour which contain no information with respect to a given verification task. We focus on exactly such an abstraction based way of dealing with large, so called industrial-sized systems and discuss its application in an industrial project aiming at the detection of service interactions in Intelligent Networks on the specification level. The concrete application of the abstraction and verification method is presented mainly by considering an example taken from the service interaction project.

The feature and service interaction problem in telecommunications systems: a survey

Today's telecommunication systems are enhanced by a large and steadily growing number of supplementary services, each of which consists of a set of service features. A situation where a combination of these services behaves differently than expected from the single services' behaviors, is called service interaction. This interaction problem is considered as a major obstacle to the introduction of new services into telecommunications networks. We present a survey of the work carried out in this field during the last decade (1988-98). After a brief review of classification criteria that exist for feature interactions so far, we use a perspective called the emergence level view. This perspective pays respect to the fact that the sources for interactions can be of many different kinds, e.g., requirement conflicts or resource contentions. It is used to rationalize the impossibility of coping with the problem with one single approach. We also present a framework of four different criteria in order to classify the approaches dealing with the problem. The general kind of approach taken, a refinement of the well known detection, resolution, and prevention categories, serves as the main classification criterion. It is complemented by the method used, the stage during the feature lifecycle where an approach applies, and the system (network) context. The major results of the different approaches are then presented briefly using this classification framework. We finally draw some conclusions on the applicability of this framework and on possible directions of further research in this field.