Biological control of bruchids infesting cowpea by the introduction of Dinarmus basalis (Rondani) (Hymenoptera: Pteromalidae) adults into farmers’ stores in West Africa

Biological control of bruchids infesting cowpea stores was achieved by introducing adults of an endemic parasitoid Dinarmus basalis (Rondani) (Hymenoptera: Pteromalidae) into farmers’ storage systems in the guinean zone in Togo and the sudano-sahelian zone in Burkina Faso. In the guinean zone, introduction of 20 or 40 pairs of D. basalis adults at the beginning of storage and again 15 days later reduced the development of the bruchid populations after 5 months of storage. Consequently, weight losses from 25 kg batches of treated cowpea seeds were lower than 10% as compared with around 30% in controls. In the sudano-sahelian zone, an introduction of 40 pairs of D. basalis adults at the beginning of storage and again 15 days later was effective, also maintaining seed weight losses from 25 kg batches at less than 10%. These results illustrate that biological control of bruchids by the introduction of D. basalis adults into farmers’ cowpea storage systems is possible in the two climatic zones of Western Africa, and produces better cowpea seed quality. However, the introduction must take place right at the beginning of storage, and the number to be introduced must take into account the initial rate of seed infestation by the bruchids.     

Approaches for introducing TMN in legacy networks: a critical look

Introducing the telecommunications management network (TMN) into a legacy network is generally an uphill battle. This article provides a critical review of the two key approaches used in the industry for introducing TMN interfaces into legacy networks. Before the analysis, it is of prime importance to establish some ground rules. There is currently no common understanding of what introducing TMN into a legacy network means, as there is no common understanding of what introducing TMN into a network means. We start by analyzing what introducing TMN into a legacy network means, and then study, successively, the bottom-up and top-down approaches. Finally, a cost trade-off analysis is made     

Signaling for multimedia conferencing in 4G: the case of integrated 3G/MANETs

Fourth-generation wireless systems are composed of coexisting and cooperating legacy and new networks. Mobile ad hoc networks are examples of new networks. They have several attractive characteristics and are gaining more and more momentum. Their integration with legacy third-generation networks is now being contemplated. Multimedia conferencing is the basis of a wealth of applications, including video conferences, multiparty games, and distance learning. Signaling is the central nerve of multimedia conferencing. It establishes, modifies, and tears down multimedia conferencing applications. This article is devoted to the signaling aspects of multimedia conferencing in 4G and focuses on the specific case of integrated 3G/MANETs. It reviews the standard 3G architecture and the emerging architectures for MANETs. This review shows that none of them is suitable for integrated 3G/MANETs. We propose a new architecture based on application-level clusters and conference gateways. We have implemented a prototype using the session initiation protocol (SIP) technology.     

Isolating faulty routing tables in SS7 networks: present and future

The author presents the standardized method used to isolate faulty routing tables in SS7 packet switched networks, and suggests an alternative for the future. The present method used has a drawback: the extra load it induces on the network. Furthermore, it requires the audit logic, with its associated software packages, in all the SS7 nodes. The alternative suggested by this article does not induce any extra load on the network. It does not require any special audit logic in the SS7 nodes. However, it requires a TMN infrastructure. There is no doubt that TMN will gradually become a reality. But before TMN products are available on a large scale, SS7 network operators will have to do with the existing method. Routing tables can be audited using the existing method, but extra care is needed in order to avoid overloading the network. Audits therefore have to be done with circumspection. They need to be carefully scheduled, especially when used to test periodically and thoroughly all the routing tables of an SS7 network     

Telecommunications management network: vision vs. reality

Since the early 1980s, the standards bodies have been specifying the telecommunications management network (TMN) principles. Millions of dollars have been spent. The TMN principles aim at being applicable across telecommunications technologies. They recommend the use of independent management networks to manage telecommunications networks, elements in the telecommunications networks (managed networks), and managing systems (in managing networks), communicating via well defined, standardized interfaces. The standards bodies envisioned TMN as a possible solution to the complex problem of telecommunications networks and services operation, administration, maintenance and provisioning (OAM and P) in the open, multivendor environment. However, the vision stumbles against the reality. Various factors still hinder the implementation of TMN-based OAM and P systems. The present article provides a tutorial on TMN by contrasting the vision and the reality     

Contrasting OSI Systems Management to SNMP and TMN

OSI systems management is a set of standards forthe management of open systems. Its acceptance by theindustry has been slower than that of SNMP, due to itsrelative complexity. However, it is gathering more and more momentum due to the increasingavailability of development tool kits and also due tothe real world implementations which have followed theuse in TMN. This paper contrasts OSI systems management to SNMP and TMN. It identifies the salientcharacteristics of OSI systems management and uses themas bases for the comparison. Aspects of X.25 managementare used for illustration purpose. OSI system management is half way between SNMP and TNM. It offersmore than SNMP, but less than TMN. SNMP, OSI systemsmanagement and TMN tackle different classes ofmanagement problems. None is a panacea andinteroperability is the key issue.     

Efficient traces’ collection mechanisms for passive testing of Web Services

Web Services are a novel approach for business-to-business interactions. Their management, especially fault and performance management, is becoming necessary for their success and emergence. Nowadays, this management is platform-dependent and does not allow third parties to be involved. In this paper, we consider management of Web Services by passive testing where the tester itself is a Web Service. We propose different architectures for observation of simple and composite Web Services. We also study a set of online traces collection mechanisms and discuss their performances in terms of required CPU/RAM resources and introduced network overhead. These performances are then maximized by selecting best locations of observers. Observation considers both functional and non-functional (QoS) properties of Web Services. The paper presents also our experiments using different observation architectures and traces collection mechanisms while observing a simple and a composite Web Service.