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Cloud environments should provide network performance isolation for co-located untrusted tenants in a virtualized datacenter. We present key properties that a performance isolation solution should satisfy, and present our progress on Gatekeeper, a system designed to meet these requirements. Experiments on our Xen-based implementation of Gatekeeper in a(More)
— Wide area networks (WAN) forward traffic through a mix of packet and optical data planes, composed by a variety of devices from different vendors. Multiple forwarding technologies and encapsulation methods are used for each data plane (e.g. IP, MPLS, ATM, SONET, Wavelength Switching). Despite standards defined, the control planes of these devices are(More)
—Fast All-Optical Circuit Switches (AOCS) are emerging as a solution to high bandwidth demands of computer networks. Unlike traditional AOCSs, which use has been restricted to provide static point-to-point circuits due to their slow circuit reconfiguration delays, recent fast AOCS prototypes are able to multiplex circuits in µs timescales. Fast AOCS(More)
Dynamic optical interconnects using fast Optical Circuit Switches (OCS) are emerging as a scalable and energy efficient alternative to increasing network demands. Initial concerns regarding slow switching speeds of OCSs were recently overcome, with prototypes enabling circuit setup in a few microseconds. This can potentially broaden the classes of traffic(More)
OBJECTIVE To develop an assessment tool to evaluate the efficiency of federal university general hospitals. METHODS Data envelopment analysis, a linear programming technique, creates a best practice frontier by comparing observed production given the amount of resources used. The model is output-oriented and considers variable returns to scale. Network(More)
The collaboration effort in developing a Carrier SDN demonstration is described, demonstrating provisioning and optimization of bandwidth services across a multi-vendor network comprising router and transport networking layers. 1. Introduction With the recent advances in converged transport networks that integrate OTN switching along with optical(More)
Hepatic tumors in children account for only 1 to 5% of all pediatric tumors. Hepatic hemangioma is, however, the third most common tumor of the liver in childhood. We report a case of an antenatal diagnosis of a hepatic tumor detected on a first obstetric ultrasound, at 26(th) week of gestation. It revealed a complex, predominantly solid hepatic lesion with(More)
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