Abstract

We consider the problem of allocating bandwidth to competing flows in an MPLS network, subject to constraints on fairness, efficiency, and administrative complexity. The aggregate traffic between a source and a destination, called a flow, is mapped to label switched paths (LSPs) across the network. Each flow is assigned a preferred ('primary') LSP, but traffic may be sent to other ('secondary') LSPs. Within this context, we define objectives for traffic engineering, such as fairness, efficiency, and preferred flow assignment to the primary LSP of a flow ('Primary Path First', PPF). We propose a distributed, feedback-based multipath routing algorithm that attempts to apply additive-increase and multiplicative-decrease (AIMD) to implement our traffic engineering objectives. The new algorithm is referred to as multipath-AIMD. We use ns-2 simulations to illustrate the fairness criteria and PPF property of our multipath-AIMD scheme in an MPLS network. Document type: Part of book or chapter of book

Abstract

Peer-to-peer networks have often been touted as the ultimate solution to scalability. Although cooperative techniques have been initially used almost exclusively for content lookup and sharing, one of the most promising application of the peer-to-peer paradigm is to capitalize the bandwidth of client peers to quickly distribute large content and withstand flash-crowds (i.e., a sudden increase in popularity of some online content). Cooperative content distribution is based on the premise that the capacity of a network is as high as the sum of the resources of its nodes: the more peers in the network, the higher its aggregate bandwidth, and the better it can scale and serve new peers. Such networks can thus spontaneously adapt to the demand by taking advantage of available resources. In this paper, we evaluate the use of peer-to-peer networks for content distribution under various system assumptions, such as peer arrival rates, bandwidth capacities, cooperation strategies, or peer lifetimes. We argue that the self-scaling and self-organizing properties of cooperative networks pave the way for cost-effective, yet highly efficient and robust content distribution. Document type: Part of book or chapter of book

Abstract

The main contribution of this paper is a new online routing algorithm, called Dynamic Online Routing Algorithm (DORA), for dynamic setup of bandwidth guaranteed paths in MPLS networks. The goal of DORA is to accept as many network path setup requests as possible by carefully mapping paths with reserved bandwidth evenly across the network. The key operation behind DORA is to avoid routing over links that: 1) have high potential to be part of any other paths, and 2) have less residual bandwidth available. We compare DORA against other existing constraint-based routing algorithms based on two performance metrics: path setup rejection ratio and percentage of successful reroutes. Our result shows that DORA performs better than the other algorithms in both metrics. Document type: Part of book or chapter of book

Abstract

Naval at sea (maritime tactical) networks are characterised by a dynamic, heterogeneous, and low-bandwidth environment. There is a critical need for Traffic Engineering (TE) mechanisms to support traffic prioritisation and resource optimisation in this environment. A desirable management service in this environment is end-to-end guaranteed bandwidth for critical application flows. Solutions such as RSVP are not appropriate for the maritime environment where links are error prone and easily overloaded. This paper describes the Resource Reservation Service (RRS), a policy-enabled flow-based TE management service developed specifically for the low-bandwidth, high-error rate, and mobility of the maritime environment. This service includes several novel features including multi-path probing, bi-directional reservations, and full policy control. The value of multi-path probing is demonstrated by simulation. Document type: Part of book or chapter of book

Abstract

In today’s ever more complex IT networked computing environment, it is becoming increasingly necessary to control and automate traditional tasks of provisioning, monitoring and management of network bandwidth and resources. In this paper, we propose an intelligent traffic engineering system to deliver next-generation provisioning and management network services. The proposed solution is capable of providing autonomic control of networks to provision bandwidth, routing and QoS to meet user SLA expectations, and dynamically engineer and manage traffic for optimal stability and performance. Document type: Part of book or chapter of book

Abstract

This paper focuses on the selection of bandwidth-guaranteed channels for communication sessions that require it. The basic idea comes from Minimum Interference Routing: select a feasible path that puts the least possible restriction on the transmission capacity offered by the network for other communicating parties. This is achieved by circumventing some critical bottleneck links. The main contribution of the paper is a method to assess the degree of link criticality facilitating efficient route precomputation even in the case, when up to date resource availability information is not immediately available. Document type: Part of book or chapter of book

Abstract

Date of Conference: 29-31 May 2007 Conference Name: 11th International IFIP TC6 Conference, ONDM 2007 We propose an online traffic engineering (TE) scheme for efficient routing of bandwidth guaranteed connections on a Multiprotocol label switching (MPLS)/wavelength division multiplexing (WDM) network with a traffic pattern varying with the time of day. We first consider the problem of designing the WDM virtual topology utilizing multi-hour statistical traffic pattern. After presenting an effective solution to this offline problem, we introduce a Dynamic tRaffic Engineering AlgorithM (DREAM) that makes use of the bandwidth update and rerouting of the label switched paths (LSPs). The performance of DREAM is compared with commonly used online TE schemes and it is shown to be superior in terms of blocked traffic ratio. Document type: Part of book or chapter of book

Abstract

This paper describes two traffic engineering techniques for implementing proportional differentiated services based on Multiprotocol Label Switching constraint based routing. Both use a dynamic bandwidth allocation scheme to modify the bandwidth reserved by each traffic class according to the current network load. The first scheme uses an adaptive algorithm that qualitatively determines the required average throughput per source for each class and moves bandwidth between classes for each path as necessary. The second scheme mathematically divides the existing bandwidth through the traffic classes for each path. The quality of service that users get with both techniques is assessed by simulation and compared with a fixed bandwidth allocation scheme. 5th IFIP International Conference on Network Control & Engineering for QoS, Security and Mobility Red de Universidades con Carreras en Informática (RedUNCI) Document type: Part of book or chapter of book

Abstract

In this paper, we present an analysis on optimization and risk management in Communication Networks (CNs). The model is proposed for offline traffic engineering optimization, which takes a centralized view of bandwidth allocation, performance control, and risk control of network profit shortfall. First, we introduce a linear penalty cost in the CN optimization model and derive the optimal bandwidth capacity with the penalty cost. Then, we use the mean-variance approach to analyze the profit shortfall risk in CNs. Finally, numerical results are shown to reveal the impact of the penalty cost on the CNs performance. Document type: Part of book or chapter of book

Abstract

In traditional channelized multiple access systems, such as TDMA and FDMA, each user is assigned a fixed amount of bandwidth during the whole connection time, and the teletraffic performance in terms of time congestion, call congestion and traffic congestion can easily be obtained by using the classical Erlang-B formula. However, with the introduction of adaptive modulation and coding (AMC) scheme employed at the physical layer, the allocation of bandwidth to each user is no longer deterministic, but dynamically based on the wireless channel conditions. Thus a new connection attempt will be blocked with a certain probability depending on the state of the system and the bandwidth requirement of the connection attempt. In this paper, we present an integrated analytical model of multi-rate loss system with state-dependent blocking to evaluate the performance of multi-class OFDM-TDMA systems with AMC scheme. Document type: Part of book or chapter of book