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The role of OSS in protecting the network
The communication network infrastructure is one of the fundamental elements of today’s critical infrastructures. Many other infrastructures, which are essential for a functioning economy and society, such as energy, water, and transportations, depend on a reliable and integer communications infrastructure. It is, thus, worthwhile considering how today’s networks achieve the required levels of reliability and integrity. In this context, the operation support system (OSS) is the critical part of the network itself, because it oversees the proper operation of the network. The managed network Typically, a network consisting of transmission links and exchange nodes (switches and routers) needs to be managed for a variety of reasons. Networks have grown over the years to become one of the most complex artefacts humankind has invented. In telecommunications, the TMN standards series of ITU-T are the main standards in the management area. The Telecommunication Management Network (TMN) is conceptually a separate network which interfaces a telecommunications network at several different points. The management functions are satisfying requirements that are organised in functional areas, according to the FCAPS principle (Fault, Configuration, Accounting, Performance, Security). The transmission links and exchange nodes are connected via a data communication network to one or more operations systems. The operations systems perform most of the management functions either automatically or via human intervention. The most important feature of TMN in view of the robustness and reliability of the whole network is the conceptual separation between the network which is managed and the network which transfers the management information. Another important element of the TMN architecture is that it defines a structure for the multiple levels of management responsibility that exist in real networks, known as the Logical Layered Architecture. This has the advantage that understanding and distinguishing the various management responsibilities becomes easier. Separating the management network from the telecommunications network prevents potential problems with fault management. Even in the case of a failure in the telecommunications network, management will still be able to access the failing components. The down-side of this concept is that additional equipment and transmission systems are required for the management network, meaning increased cost. Nevertheless, the cost is accepted in favour of “five nines” availability, meaning 99,999 % availability of the telecommunications network. Being a separate network with well-controlled interconnection points, it is also easier to introduce appropriate security measures to protect the management network.
New requirements for NGN? The vision of next generation networks (NGN) poses significant challenges to an appropriate architecture for operation, administration and maintenance of future networks and services. Along with the pressure arising from deregulation, competition and rapid technology change, the increasing awareness of the importance of the network as part of the critical infrastructure of society poses additional requirements that are being formulated currently. From a perspective of reliability and trustworthiness these requirements inevitably fall in the functional areas of Fault and Security (according to FCAPS). In many countries the inter-governmental and emergency communications rely to a degree of up to 90 % on public networks. This is the reason why in many countries work is under way to formulate the standards that contribute and support national security and emergency preparedness communications. The issue is also being addressed at the ITU-T in order to foster international co-operation in this area. New OSS interconnection standards take into account the need for interchange of critical network and service management information between different service providers and the customers. Initiatives have been established to facilitate the interchange of information on service and network disruptions, such as the US National Coordinating Center for Telecommunications. Conclusion The network OSS has long been recognised as a critical success factor for supporting existing and emerging business challenges. But the importance of the OSS to support the critical infrastructure of the information society has indeed been identified and is being addressed. The cooperation at the international level has also been recognised and the relevant standardisation bodies, such as the ITU-T and the TeleManagement Forum, are working to establish the necessary standards. It is now up to the commitment of the involved stakeholders, whether nations or organisations, to support this effort as well, since it is not only a technological issue but also includes the learning component for humans involved in the network operations chain. Please send us your comments on this article. |
