77 research outputs found
On Virtualizing Ethernet Switches
Abstract—We are interested in exploring how to virtualize network switches in order to create multiple logical switches from one physical switch. The motivation behind this is to be able to support multiple research-and-education (R&E) projects by offering each of them a logical switch that could coexist with other R&E projects ’ logical switches, so that each would have the equivalent of their own switch. We propose an approach for virtualizing off-the-shelf Ethernet switches that have built-in support for creating isolated bandwidth partitions on their data-plane interfaces. Our solution is to implement two software modules that are run external to the switches, a slice scheduler and a Slice Administration Controller (SAC). We applied our approach to virtualizing a specific Ethernet switch, i.e., the Force10 E600 model. We describe our implementation, and show how a slowdown of 3 % to 26%, based on the type of administrative command issued, is experienced when using the SAC. I
CHEETAH: Circuit-Switched High-Speed End-to-End Transport Architecture Testbed
We propose a circuit-switched high-speed end-to-end transport architecture (CHEETAH) as a networking solution to provide high-speed end-to-end circuit connectivity to end hosts on a dynamic call-by-call basis. Not only is it envisioned as a complementary service to the basic connectionless service provided by today’s Internet; it also relies on and leverages the presence of this service. Noting the dominance of Ethernet in LANs and SONET/SDH in WANs, CHEETAH circuits will consist of Ethernet segments at the ends and Ethernet-over-SONET segments in the wide area. In this article we explain the CHEETAH concept and describe a wide-area experimental network testbed we have deployed based on this concept. The network testbed currently extends between Raleigh, North Carolina, Atlanta, Georgia, and Oak Ridge, Tennessee, and uses off-the-shelf switches. We have created CHEETAH software to run on end hosts to enable automated use of this network by applications. Our first users of this network testbed and software will be the Terascale Supernova Initiative (TSI) project researchers, who plan to use this network for large file transfers and remote visualizations
Designing a Hadoop system based on computational resources and network delay for wide area networks
This paper proposes a Hadoop system that considers both slave server’s processing capacity and network delay for wide area networks to reduce the job processing time. The task allocation scheme in the proposed Hadoop system divides each individual job into multiple tasks using suitable splitting ratios and then allocates the tasks to different slaves according to the computational capability of each server and the availability of network resources. We incorporate software-defined networking to the proposed Hadoop system to manage path computation elements and network resources. The performance of proposed Hadoop system is experimentally evaluated with fourteen machines located in the different parts of the globe using a scale-out approach. A scale-out experiment using the proposed and conventional Hadoop systems is conducted by executing both single job and multiple jobs. The practical testbed and simulation results indicate that the proposed Hadoop system is effective compared to the conventional Hadoop system in terms of processing time
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Methods for Objective and Subjective Evaluation of Zero-Client Computing
Zero clients are hardware-based devices without a central processing unit (CPU) that deliver virtual desktops (VDs) from remote computing systems to users. We measured the performance of applications accessed through zero clients to study the feasibility of using this approach to provide a desktop-pc experience across a network. Performance evaluation is complicated because monitoring software cannot be downloaded to the zero clients. Therefore, we introduce a new methodology and metric to measure zero-client VD performance that is based on network-traffic analysis. We conducted objective and subjective studies to determine the sensitivity of application-specific metrics to different network conditions. The results show that the packet loss rate (PLR) impacts zero-client performance for some applications such as video streaming. Subjective tests showed a greater user sensitivity to the PLR for video streaming than for image viewing or Skype. A strong correlation was found between the objective and subjective measurements but the rate at which these measurements changed with increasing PLR differed depending on the application.NSF [CNS-1737453]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
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Final Report for the project titled "Enabling Supernova Computations by Integrated Transport and Provisioning Methods Optimized for Dedicated Channels"
A high-speed optical circuit network is one that offers users rate-guaranteed connectivity between two endpoints, unlike today’s IP-routed Internet in which the rate available to a pair of users fluctuates based on the volume of competing traffic. This particular research project advanced our understanding of circuit networks in two ways. First, transport protocols were developed for circuit networks. In a circuit network, since bandwidth resources are reserved for each circuit on an end-to-end basis (much like how a person reserves a seat on every leg of a multi-segment flight), and the sender is limited to send at the rate of the circuit, there is no possibility of congestion during data transfer. Therefore, no congestion control functions are necessary in a transport protocol designed for circuits. However, error control and flow control are still required because bits can become errored due to noise and interference even on highly reliable optical links, and receivers can, due to multitasking or other reasons, not deplete the receive buffer fast enough to keep up with the sending rate (e.g., if the receiving host is multitasking between receiving a file transfer and some other computation). In this work, we developed two transport protocols for circuits, both of which are described below. Second, this project developed techniques for internetworking different types of connection-oriented networks, which are of two types: circuit-switched or packet-switched. In circuit-switched networks, multiplexing on links is “position based,” where “position” refers to the frequency, time slot, and port (fiber), while connection-oriented packet-switched networks use packet header information to demultiplex packets and switch them from node to node. The latter are commonly referred to as virtual circuit networks. Examples of circuit networks are time-division multiplexed Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH) and Wavelength Division Multiplexing (WDM) networks, while examples of virtual-circuit networks are MultiProtocol Label Switched (MPLS) networks and Ethernet Virtual Local Area Network (VLAN) networks. A series of new technologies have been developed to carry Ethernet VLAN tagged frames on SONET/SDH and WDM networks, such as Generic Framing Procedure (GFP) and ITU G.709, respectively. These technologies form the basis of our solution for connection-oriented internetworking. The benefit of developing such an architecture is that it allows different providers to choose different connection-oriented networking technologies for their networks, and yet be able to allow their customers to connect to those of other providers. As Metcalfe, the inventor of Ethernet, noted, the value of a network service grows exponentially with the number of endpoints to which any single endpoint can connect. Therefore internetworking solutions are key to commercial success. The technical effectiveness of our solutions was measured with proof-of-concept prototypes and experiments. These solutions were shown to be highly effective. Economic feasibility requires business case analyses that were beyond the scope of this project. The project results are beneficial to the public as they demonstrate the viability of simultaneously supporting different types of networks and data communication services much like the variety of services available for the transportation of people and goods. For example, Fedex service offers a deadline based delivery while the USPS offers basic package delivery service. Similarly, a circuit network can offer a deadline based delivery of a data file while the IP-routed network offers only basic delivery service with no guarantees. Two project Web sites, 13 publications, 7 software programs, 21 presentations resulted from this work. This report provides the complete list of publications, software programs and presentations. As for student education and training (human resources), this DOE project, along with an NSF project, jointly supported two postdoctoral fellowships, three PhDs, three Masters, and two undergraduate students. Specifically, two of the Masters students were directly funded on this DOE project
Connection Control in ATM Networks
this paper, we present an add-on improvement to the PNNI scheme called parallel connection control (PCC) for the setup and release of ATM connections
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