Abstract: A capability for coping with link failures in central control plane architectures is provided. The capability for coping with link failures enables targeted reporting of link failures within the network in a manner that prevents flooding of link failure messages (LFMs) within the network. A method for reporting a failure of a link associated with a node includes detecting a failure of a link associated with the node, identifying an interface of the node associated with the failed link, identifying, from a flow table of the node, an ingress interface of the node via which a flow intended for the failed link is received, generating an LFM for the identified ingress interface, and sending the LFM via the identified ingress interface.

Abstract: In one embodiment, a system has two or more working computers, each running one or more working virtual machines (VMs), and a protection computer running corresponding protection VMs. A management station can change the levels of computer resources specified in resource-configuration files for the protection VMs, and virtualization software can re-read the resource-configuration files and change the allocation of computer resources to the protection VMs without having to shut down and re-launch the protection VMs. By initially launching the protection VMs with reduced levels of computer resources, fast and cost-effective failover protection can be provided to the working computers, where the computer resources allocated to a protection VM are enhanced only after the detection of a failure of the corresponding working VM, without having to shut down and re-launch the protection VM.

Abstract: The set T of all categories in a population of RFID tags is estimated within a specified error bound. For each of one or more frames, a reader broadcasts a probability p, a multiplicity d, a frame size M, and a seed value R to the present tags. A deterministic algorithm on each tag, and known to the reader, calculates (i) whether the tag will transmit in this frame, and, if so, (ii) in which slots the tag will transmit a single “1.” When the tags have responded, the reader calculates set T by initially assuming that all possible categories are in set T and then eliminating those categories that would have transmitted in those slots in which no tag transmitted. Alternatively, the reader initially assumes that set T is empty, and adds those categories that would have transmitted in those slots in which one or more tags did transmit.

Abstract: A method of balancing user registration lifetimes in a network is disclosed for smoothing the load of the registration server. The method of balancing user registration lifetimes in a network includes providing an initial registration lifetime for a registration request that is calculated using the time of the request and the previous history of registration requests, and in a particular embodiment, using the cumulative distribution function of the history of registration requests. The method of balancing user registration lifetimes in a network is particularly useful for handling spikes in registration traffic, and can accommodate user-specified variable lifetimes, as well dynamic user arrivals and departures. It provides effective load balancing over time for a single server, at the expense of a constant factor additive load per user, which can be amortized to near zero over the long run.