The objective of this paper is to study the performance of handoff procedures for an integrated wireless LAN/WAN infrastructure, both qualitatively and quantitatively. We make use of a proposed hierarchical mobility management scheme to evaluate the performance of a handoff procedure with a hierarchy level of one. Also, we propose a design and perform the analysis for a two-level hierarchy arch...

Extranets are a technology for creating logical views of geographically separate LANs by providing a transparent interconnection mechanism between them over a WAN As LAN bandwidths are typically higher than those of a WAN and LANs typically support stronger security features it is essential that extranets can be constructed to be both secure and high of speed The security of an extranet can be ...

90 ulticasting is the ability of a communication network to accept a single message from an application and to deliver copies of the message to multiple recipients at different locations. One of the challenges is to minimize the amount of network resources employed by multicasting. To illustrate this point, let us assume that a video server wants to transmit a movie to 1000 recipients (Fig. 1a)...

Multi-party computation (MPC) has been a very active area of research, and recent industrial deployments exist. Practical MPC is currently limited to low-latency, high-throughput network setups, i.e., local-area networks (LAN). However, many use cases require the participation different entities located in data centers, communication over wide-area (WAN). Although, constant-round exists, it hig...

Twenty years ago the typical computing installation was a centralised processing and storage resource accessed by users via telecommunication links. Modern systems however function as a network of remote processors and data resources to provide for the exchange of information between various components of the enterprise [Betz94]. The popular realisation of this model is called the client/server...

Early experiments in migrating task images from one node in a metacomputing environment to another have shown, that it is possible to achieve almost maximum data throughput in LAN networks. With WAN-connected metacomputers however, the time spent in the task migration is not negligible. Here, alternative routing paths must be used concurrently to reduce the total migration time. We present a pr...

This paper presents a new mathematical framework of a Scalable Mobility Model (SMM) to characterise user movement behaviour, which can be applied to a wide number of network scenarios ranging from Local Area Networks (LAN) to Wide Area Networks (WAN). The core technique to describe the spatial and temporal behaviour of mobile users is the introduction of a novel concept referred to as Pole of G...

Users need high speed and low latency transmission for new applications. Since Ethernet is the dominant LAN technology, service providers wish to offer new Ethernet services as Layer 2 Virtual Private Network (L2VPN), to meet the requirements of these applications. MultiProtocol Label Switching (MPLS) is one of the most suitable technologies to deploy L3VPN and can also be used to realize L2VPN...

This month’s column examines and evaluates various programming techniques for developing distributed applications. Our previous column outlined the requirements for a representative distributed application in the financial services domain. This application enables investment brokers to query the price of a stock, as well as to buy shares of stock. As shown in Figure 1, the quote service that ma...