Overlay Routing Middleware for Multimedia Communications

The rapid growth and increasing requirements for service quality, reliability had made everyone to choose the traffic engineering essential for the large public networks. The multi Protocol label switching is a protocol used when there is interaction between the traffic engineering and the overlay networks. This MultiProtocol Labeled Switching (MPLS) with the help of the nash equilibrium algorithm has given optimized performance better by reducing the latency and increasing the link utilization. But increase in link utilization will gradually increase the congestion in the network as the link is being used by all the nodes. So, to overcome this specific problem we have performed a formulation called dual programming formulation which has set of constraints that have to be satisfied, along with Open Shortest Path First(OSPF) protocol so as to reduce the maximum link utilization. We have simulated the results in five queuing models which includes BPR,PD1,PM1,MM1,MD1 using source, compliant, optimal overlay routing. The results are simulated using Ns2 with linux as platform.Link utilization is reduced based on the parameters such as traffic demands and the distance between the nodes with their respective demands.

A recent trend in routing research is the use of overlay routing to improve end-to-end QoS without changing the network-level architecture. The key of this technology is to find an alternative route that can avoid congested routes, using an overlay network. Developing cost-efficient overlay routing in terms of calculation cost and information distribution cost needed to find an alternative route is important for deploying QoS-aware overlay routing. Thus, this paper evaluates how effective overlay routing can be when the number of alternative route candidates is limited to reduce costs. Evaluation results using actual measurement data indicate that overlay routing is still effective even if alternative route candidates are limited to 1/4 of all possible alternative routes. We also discuss an overlay routing algorithm to enable us to find an appropriate route under the constraint that the number of alternative route candidates is limited.

Recent research on overlay networks has revealed that user-perceived network performance could be improved by an overlay routing mechanism. The effectiveness of overlay routing is mainly a result of the policy mismatch between the overlay routing and the underlay IP routing operated by ISPs. However, this policy mismatch causes a "free-riding" traffic problem, which may become harmful to the cost structure of Internet service providers. In the present paper, we define the free-riding problem in the overlay routing and evaluate the degree of free-riding traffic to reveal the effect of the problem on ISPs. We introduce a numerical metric to evaluate the degree of the free-riding problem and confirm that most multihop overlay paths that have better performance than the direct path brings the free-riding problem. We also discuss the guidelines for selecting paths that are more effective than the direct path and that mitigate the free-riding problem.

Traffic engineering in IP/WDM networks can be pursued in two fashions: overlay and integrated. With overlay traffic engineering, operations in one layer can be independent from those in the other layer. Traffic engineering solutions developed for either IP networks or WDM networks can be directly applied to each layer, respectively. At the present stage, an anticipated first step towards IP over WDM is to hook up IP router interfaces to optical add/drop multiplexer client add/drop ports. This forms an overlay network in which WDM serves as the server layer and IP behaves like the client layer. This overlay client-server network is a natural match to the notion of overlay traffic engineering. With integrated traffic engineering, optimization with respect to selected objectives is pursued coordinately across both the IP and WDM layers. It is made possible by mechanisms such as multi-protocol lambda switching that allows a unified control plane across both layers. With the emergence of more sophisticated hardware that integrates functionality of both IP and WDM at each network element, integrated traffic engineering can be performed more naturally and efficiently.

Overlay networks have emerged as a promising paradigm for providing customizable and reliable services at the application layer, such as fault-resilient routing, multicast, and content delivery. Among the overlay network architecture, overlay routing is an important aspect of the overlay network design. In this paper, we develop a one-hop source routing, called heuristic-K algorithm using Ant Colony Optimization, to allow individual nodes to optimize route selection based on specific metrics like delay, loss rate, or throughput. Moreover, due to the selfish operating manner of overlay routing, we also take the traffic engineering element into consideration in the design process of our proposal. The experimental results demonstrate the effectiveness of the routing algorithm.

A new traffic engineering manager for DiffServ/MPLS networks: design and implementation on an IP QoS Testbed

Inter-domain policy violations in multi-hop overlay routes: Analysis and mitigation

Distributed hash table (DHT)-based overlay networks, represented by Pastry, CAN, and Chord, offer an administration-free and fault-tolerant application-level overlay network. While elegant from a theoretical perspective, these systems have some disadvantages. First, they rely on application-level routing, which may be inefficient with respect to network delays and bandwidth consumption. Second, they typically construct a homogeneously structured overlay even though nodes in these networks usually have varying physical connectivity and packet-forwarding capacities. In this paper, we propose two approaches for constructing an auxiliary expressway network to take advantage of the different connectivity, forwarding capacities, and availabilities of the nodes. As a result, we are able to reconcile the conflict of presenting the applications with a homogeneous structured overlay to simplify management, while at the same time taking advantage of the inherent heterogeneity of the underlying physical network to speed up routing. Our simulation results show that our expressway can achieve close to optimal routing performance (on average, 1.07 and 1.41 times optimal routing for an Internet-like topology and a large synthesized transit-stub graph, respectively) in overlay networks.

The new trends in the service area cause a change on the service provisioning architecture and scheme. The most obvious differences are multimedia services and multiparty communications. The existing service providing schemes can hardly catch up with these new trends. A few years ago, multimedia service was not applicable to the public networks, because of the shortage of transmission bandwidth. Nowadays, situations in the transmission capabilities of the public networks have been continuously changed. Moreover, developing ATM technology is the most powerful driving force towards a B-ISDN era. The essential components that constitute the traditional schemes have been defined in the characteristic categories of transmission, terminal and switching. In this paper, we define an additional component for the new B-ISDN services on public networks. We proposed a service provisioning architecture to be implemented on an ATM-based switching system as a uniform service management function called Service Node System (SNS) for enterprise networks. The SNS will provide a high degree of efficiency for providing a variety of new services on ATM-based telecommunication networks. We define various functions of the architecture and describe interaction schemes among its function modules.

We present different design options to implement Augmented Multipath Transmission Control Protocol (A- MPTCP) communications via a Locator/Identifier Separation Protocol (LISP) Traffic Engineering (TE) overlay network. MPTCP allows a TCP connection using multiple subflows to maximize resource usage. LISP is a routing and addressing architecture that provides new semantics for IP communications, by separating the device identity (endpoint identifier) from its location (routing locator) using two different numbering spaces. Our proposition is to adopt a LISP overlay network with traffic engineering capabilities to steer MPTCP subflows across wide-area Internet networks. The resulting augmentation consists of a subflow forwarding that can reach edge bottleneck capacity and surround inter-domain transit bottlenecks and inefficient paths. It can be particularly useful for cases where, even if endpoints are single-homed, inter-domain path diversity can be grasped by the LISP-TE network overlay. We specify the different modes at which this augmentation can take place, from stateless and light modes with very limited management in the network, to stateful and advanced modes implementable by a network provider desiring a higher control on the network. Based on extensive experimentation on the worldwide LISP testbed, we show that the achievable gains up 25% in throughput, while identifying required further improvements.

This paper intends to establish a production control and safety management system for the passenger transportation depot to improve the level of information. First of all this paper analyzes the necessity and significance of the system. On the bases, describes the design objectives and design range of the system. And then this paper designs the overall structure of the system, proposes the logical architecture and technical architecture program of the system, and then designs the system network solution. Finally this paper carries out a detailed functional design of the system, and the system is divided into two subsystems, the command center subsystems and safety management subsystem, and both of the two subsystems' functional modules are designed in detail.

As a result of its success, Wi-Fi has been promoted as an access technology to provide full internet connectivity in the municipal area. Supporting application QoS by managing resource provisioning is an important challenge for wireless network operators. This paper proposes a traffic engineering model for managing a Voice over Wi-Fi service in a municipal area with stationary and mobile clients. Our proactive algorithm guarantees the connectivity of the mobile clients while maximizing the number of stationary stations. Simulation results show substantial QoS improvements for mobile clients and a near optimal utilization of the capacity of the wireless access network next to the congested hotspots.

This paper describes the development process of the mobile point exchange system from demand analysis, outline design, detailed design and implementation. The system combines current business needs and uses collaborative filtering recommendation algorithms to solve the problem of how to calculate data similarity. The system is written in JAVA language, and uses a layered architecture model to separate business modules and functional modules. The front-end uses HTML, FreeMarker and Vue technologies to achieve page display and data rendering, and the persistence layer framework uses Mybatis to implement customized SQL, Stored procedures and advanced mapping, through the Spring framework to realize the management of JAVABean, dependency injection and transaction management, and finally realize the point redemption function.

In this paper we study the problem of enabling uninterrupted delivery of messages between endpoints, subject to spatially correlated failures in addition to independent failures. We developed a failure model-independent algorithm for computing routing paths based on failure correlations using both a-priory failure statistics together with available real-time monitoring information. The algorithm provides the most cost-efficient message routes that are potentially comprised of multiple simultaneous paths. We also designed and implemented an Internet-based overlay routing service that allows applications to construct and maintain highly resilient end-to-end paths. We have deployed our system over a set of geographically distributed Planetlab nodes. Our experimental results illustrate the feasibility and performance of our approach.

Many important cloud services require replicating massive data from one datacenter (DC) to multiple DCs. While the performance of pair-wise inter-DC data transfers has been much improved, prior solutions are insufficient to optimize bulk-data multicast, as they fail to explore the capability of servers to store-and-forward data, as well as the rich inter-DC overlay paths that exist in geo-distributed DCs. To take advantage of these opportunities, we present BDS, an application-level multicast overlay network for large-scale inter-DC data replication. At the core of BDS is a fully centralized architecture, allowing a central controller to maintain an up-to-date global view of data delivery status of intermediate servers, in order to fully utilize the available overlay paths. To quickly react to network dynamics and workload churns, BDS speeds up the control algorithm by decoupling it into selection of overlay paths and scheduling of data transfers, each can be optimized efficiently. This enables BDS to update overlay routing decisions in near realtime (e.g., every other second) at the scale of multicasting hundreds of TB data over tens of thousands of overlay paths. A pilot deployment in one of the largest online service providers shows that BDS can achieve 3-5 x speedup over the provider's existing system and several well-known overlay routing baselines.