We consider the problem of bulk data transfers and bandwidth sharing in the context of grid infrastructures. Grid computing empowers high-performance computing in a large-scale distributed environment. Network bandwidth, which makes the expensive computational and storage resources work in concert, plays an active role on carrying grid applications traffic. Due to specific traffic patterns and application scenarios, grid network resource management encounters new challenges. From the bandwidth sharing perspective, this article looks at network bandwidth shared among computing and storage elements. Referred to as short-lived, grid data requests with transmission window and volume are scheduled in the network. By manipulating the transmission window, the request accept rate and network resource utilization are to be optimized. The formulated optimization problem is proven NP-complete. Associated with proposed heuristics, simulations are carried out to illustrate the pros and cons of each bandwidth sharing strategy and its application scenarios. A tuning factor, that allows for adapting performance objective, is introduced to adjust network infrastructure and workload

While grid computing reaches further to geographically separated clusters, data warehouses, and disks, it poses demanding requirements on end-to-end performance guarantee. Its pre-defined destinations and service criteria ease the performance control; however, expensive resources and equipments used by grid applications determine that optimal resource sharing, especially at network access points, is critical. From the resource reservation perspective, this article looks at communication resources shared by grid sites. Two resource request scenarios have been identified, aiming at optimizing the request accept rate and resource utilization. The optimization problems, proven NP-complete, are then solved by heuristic algorithms. Simulation results, aside from showing satisfying results, illustrate the pros and cons of each algorithm

As the DiffServ architecture is gaining ground, traffic engineering requires major adjustments. In addition, the measurement-based strategy gas been widely adopted owing to its advantages of flexibility and easy adaptation. This article reviews measurement-based dropping schemes. Based on the definition and investigation of the "packet shortage" phenomenon, an enhanced dropping scheme for the proportional differentiated packet loss, referred to as "debt-aware," is proposed. Simulation parameters, as compared to a typical proportional dropping mechanism. More simulations have been applied to demonstrate the merits of this improved method.

Carrying IP traffic over connection-oriented networks requires the use of bandwidth allocation schemes at gateways or network interfaces. A new virtual queue occupancy, which is more accurate than the classical queue status parameter, is being proposed for periodic bandwidth allocation. Based on this virtual queue occupancy, an enhanced approach for lossless services, referred to as LAVQ, is simulated and evaluated in an IP/SONET environment. Simulations show that LAVQ outperforms its counterpart LAQ in terms of bandwidth utilization, without compromising the performance of queue occupancy.