Today, various real-time services, like audio/videoconferencing, and telemedicine, are being deployed over the Internet. This requires the network to provide the guarantee of the service provided to the receiver. The needs of the applications are specified in terms of the Quality of Service (QoS) metrics like desired bandwidth, response time, loss rate, expected reliability etc. Support for QoS needs to be provided at each of the layers of the protocol stack for overall efficiency in network utilization.
Routing algorithms supporting QoS differentiation differ from traditional routing algorithms in that, in QoS routing, the path from the source to the destination needs to satisfy multiple constraints simultaneously, while in conventional routing, routing decisions are made based only on a single metric such as cost or delay. However, it is well known that path selection subject to two or more independent additive metrics is NP-complete, which means that there is no efficient(polynomial) exact solution for the general multi-constrained path(MCP) selection problems.
In this paper, we describe the outline of distributed QoS routing problems and propose a mean field annealing(MFA) heuristic algorithm to solve the MCP problem.

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Daido Steel Co., Ltd developed a computerized on-line production control system using data communication network named COPS in Chita plant in 1974. Since then, our data communication network has been growing wider and more rapid, and it has been applied to various uses.
We started using HD (High-speed Digital line) among offices and plants, and integrating data and voice communication in 1986.
The characteristics of our communication network are:
•Toll dial (telephone, FAX, personal computer communication)
•Connection of all computers and terminals (DNS)
•Inter-corporate communication network (DAIDO-NET), and the aims of expansion are:
•Higher grade •More reliability •Better economy.

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This paper presents a new routing approach to extend the effective lifetime of mobile ad hoc networks (MANET) considering both residual battery energy of the participating nodes and routing cost. As the nodes in ad hoc networks are limited in power, a power failure occurs if a node has insufficient remaining energy to send, receive or forward a message. So, it is important to minimize the energy expenditure as well as to balance the remaining battery power among the nodes. Cost effective routing algorithms attempt to minimize the total power needed to transmit a packet which causes a large number of nodes to loose energy quickly and die. On the other hand, lifetime prediction based routing algorithms try to balance the remaining energies among the nodes in the networks and ignore the transmission cost. These approaches extend the lifetime of first few individual nodes. But as nodes spend more energy for packet transfer, power failures occurs, within short interval resulting more number of total dead node earlier. This reduces the effective lifetime of the network, as at this stage successful communication is not possible due to the lack of forwarding node. The proposed method keeps the transmission power in modest range and at the same time tries to reduce the variance of the residual energy of the nodes more effectively to obtain the highest useful lifetime of the networks in the long run. Nonetheless, movement of nodes frequently creates network topology changes via link breaks and link creation and thus effects on the stability of the network. So, the pattern of the node movement is also incorporated in our route selection procedure.

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The widespread adoption of IP-based telecommunication core networks is leading to a paradigm shift in international interconnection where the traditional Time-Division Multiplexing (TDM) interconnection between telecommunication networks is being replaced by IP interconnection. IP eXchange (IPX) is an emerging paradigm in international IP interconnection that has novel requirements, such as an end-to-end Quality of Service (QoS) guarantee across multiple carriers. IPX is a future direction for international telecommunications, but it is not easy to understand the overall concept of IPX because it is derived from a wide variety of services, technical knowledge, and telecommunication backgrounds. The confusion and complexity of the technical elements hinder the development of IPX. Thus, this paper clarifies the state-of-the-art technical elements from an IPX perspective and discusses ongoing challenges and emerging services on IPX, particularly end-to-end QoS, Voice over IP issues, IP Multimedia Subsystem (IMS) interworking, and Long Term Evolution (LTE) roaming. This paper also surveys published academic research studies that were not focused primarily on IPX but which are likely to provide potential solutions to the challenges.

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