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It has been suggested that one of the most significant reasons for Multi-Protocol Label Switched (MPLS) network deployment is network traffic engineering. The goal of traffic engineering is to make best use of the network infrastructure and this is facilitated by the explicit routing feature of MPLS which allows the potential addressing of many shortcomings associated with current IP routing schemes. This paper describes a software system called Routing and Traffic Engineering Server (RATES) developed for MPLS traffic engineering. It also describes some new routing ideas incorporated in RATES for MPLS explicit path selection. The RATES implementation consists of a policy and flow database, a browser based interface for policy definition and entering resource provisioning requests, and a COPS (Common Open Policy Service) server-client implementation for communicating paths and resource information to edge routers. RATES also uses the OSPF topology database for dynamically obtaining link...

Many wireless applications, such as ad-hoc networks and sensor networks, require decentralized operation in dynamically varying environments. We consider a distributed randomized network coding approach that enables efficient decentralized operation of multi-source multicast networks. We show that this approach provides substantial benefits over traditional routing methods in dynamically varying environments.

We present a distributed randomized network coding approach for transmission and compression of information in general multi-source multicast networks. Network nodes independently and randomly select linear mappings from inputs onto output links over some field. We show that this achieves optimal capacity with probability rapidly approaching 1 with the code length. We also demonstrate that randomized coding performs compression when necessary in a network, generalizing error exponents for linear Slepian-Wolf coding in a natural way. Benefits of this approach are decentralized operation and robustness to network changes or link failures. We show that this approach can take advantage of redundant network capacity for improved performance and robustness. We illustrate some potential advantages of randomized network coding over routing in two examples of practical scenarios: distributed network operation and online algorithms for networks with dynamically varying connections. Our mathematical development of these results also provides a link between network coding and network flows/bipartite matching, leading to a new bound on required field size for centralized network coding on general multicast networks. 1

Abstract—Multicast traffic engineering (TE) has recently attracted significant attention given the emergence of point-to-multipoint multimedia content delivery over the Internet. Existing multicast resource provisioning solutions tend to use explicit-routing based TE with multiprotocol label switching (MPLS) tunnels. In this paper, we shift away from this overlay approach and address native IP multicast traffic engineering based on link state routing protocols. The objective is that, through plain Protocol Independent Multicast-Sparse Mode (PIM-SM) shortest path routing with optimized multitopology IGP (MT-IGP) link weights, the resulting multicast trees are geared towards minimal consumption of bandwidth resources. We apply genetic algorithms (GA) to the calculation of optimized MT-IGP link weights that specifically cater for engineered PIM-SM routing with statistical bandwidth guarantees in multimedia content delivery. Our evaluation results show that GA-based multicast traffic engineering consumes significantly less bandwidth in comparison to conventional IP approaches while also exhibiting higher service availability. Index Terms—Link weight optimization, multicast routing, multimedia content delivery, Steiner tree, traffic engineering. I.

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Abstract. Many group communication applications have real-time constraints. Since multicast serves as a natural framework for such applications, it is desirable to support quality of service (QoS) guarantees for multicast. Limiting the amount of processing inside the network core has been recognized as a key for any QoS solution to be scalable and accordingly any QoS solution for multicast should not require core routers to perform extensive per-flow operations. We propose an architecture to implement distributed admission control for multicast flows with heterogeneous user requirements while not requiring core routers to perform any admission control. Our admission control framework guarantees that a request is only admitted if there is sufficient bandwidth available and only requires the edge routers of a domain to take admission decisions. An intra-domain signaling mechanism is used in conjunction with the admission control framework to install the forwarding state inside the network core. We show that using our architecture, the requirements for both installing and maintaining the forwarding state in core routers, are similar to that in a best-effort multicast, thus, providing the QoS control plane functionality with negligible additional complexity inside network core. 1

We study wireless multihop energy harvesting sensor networks employed for random field estimation. The sensors sense the random field and generate data that is to be sent to a fusion node for estimation. Each sensor has an energy harvesting source and can operate in two modes: Wake and Sleep. We consider the problem of obtaining jointly optimal power control, routing and scheduling policies that ensure a fair utilization of network resources. This problem has a high computational complexity. Therefore, we develop a computationally efficient suboptimal approach to obtain good solutions to this problem. We study the optimal solution and performance of the suboptimal approach through some numerical examples. Categories and Subject Descriptors