Traditional IP Networks Research Articles

An Innovative Solution for Dynamic Bandwidth Engineering in IP/MPLS Networks with QoS Support

This paper reports an original module for effectively handling bandwidth resources in a multi-service MPLS network. This module, named bandwidth engineering, allows accommodating more traffic with respect to traditional IP networks, reducing the network blocking probability, while preserving Class of Service (CoS) requirements. It consists of an algorithm that handles priority between label switched paths associated to different classes of services, and of a dynamic routing algorithm that works with the bandwidth constraint. Simulation results are reported to assess the validity of the proposed solution.

Comparative analysis of path computation techniques for MPLS traffic engineering

We consider the problem of computing traffic engineered paths for requests having bandwidth and delay requirements, when these requests arrive in the network independent of one another. Providing bandwidth guarantees to applications has been important in networks offering service differentiation. With the increase in the number of real-time applications in the Internet, provision of delay guarantees is also receiving much attention. This necessitates the development of sophisticated path selection algorithms which deviate from the shortest-path routing philosophy in traditional IP networks. While these algorithms perform well from the perspective of satisfying application requirements, they often do not take into account long term effects on the network state. One of the major concerns of a service provider is to run the network at maximum utilization while reducing network costs and preventing congestion in the network. For this reason, providers are looking at traffic engineering (TE) to automate path selection procedures and to maintain network loading at an optimal level. In this paper we propose two TE path selection algorithms that consider the application's delay–bandwidth requirements as well as the TE constraints on the network. We compare the proposed algorithms to existing path computation solutions and present results that show that by considering these additional constraints, improvement is achieved in terms of reduction in request blocking probability, reduction in network costs and load distribution.

Active network supports for mobile IP

The basic mobile IP protocol is difficult to implement on the traditional IP network and not flexible and efficient under certain conditions. For example, firewalls or boundary routers may drop packets sent by mobile nodes for security reasons. Traditional networking devices such as routers cannot dynamically load and unload extended services to achieve different qualities of services. In this paper, a new scheme of using the active network to support the mobile IP is presented. The Softnet, a prototype of active networks based on mobile agents, is introduced. The active network is characterized by the programmability of its intermediate nodes and therefore presents dynamic and flexible behaviors. Special services can be dynamically deployed onto the active nodes in the Softnet. This property is definitely required in implementing the mobile IP protocols. The Softnet supports not only the basic mobile IP protocol but also other extended mobile IP protocols. Virtual networks for mobile IP services are dynamically formed by mobile agents in the Softnet to provide different qualities of services.

Traffic engineering standards in IP-networks using MPLS

The explosive growth of the Internet over the last few years has made the IP protocol suite the most predominant networking technology. Furthermore, the convergence of voice and data communications over a single network infrastructure is expected to happen over IP-based networks. Traditional IP-networks offer little predictability of service, which is often unacceptable for applications such as telephony, as well as for emerging and future real-time applications such as telemedicine. One of the primary goals of traffic engineering is to enable networks to offer predictable performance. Due to the need for better traffic control by network service providers, there has been considerable activity in the Internet Engineering Task Force to develop standards for traffic engineering in IP-based networks. This article discusses the direction taken by the IETF and some of the recent standardization efforts for traffic engineering using multiprotocol label switching (MPLS). Our primary focus is on the signaling protocols developed for this purpose.

Real-time voice over packet-switched networks

We discuss the architecture and technical viability of transporting real-time voice over packet-switched networks such as the Internet. The value of integrating voice and data networks onto a common platform is well known. The telephony industry has proposed the ATM standard as a means of upgrading the Internet to provide both real-time and data services. In contrast, voice services may be added to traditional IP networks that were originally designed for data transmission alone. We consider the feasibility and expected quality of service of audio applications over IP networks such as the Internet. In particular, we examine possible architectures for voice over IP and discuss measured Internet delay and loss characteristics.