Multi-Terabit/s IP Switching with Guaranteed Service for Streaming Traffic

traffic on the Internet continues to grow exponentially, there is a real need to solve transmission and switching scalability. Moreover, future Internet traffic will be dominated by streaming media flows, such as video-telephony, video-conferencing, 3D video, virtual reality, and many more. Consequently, network solutions will need to offer quality of service and traffic engineering together with the above mentioned scalability - i.e., over-provisioning is not likely be a viable solution to accommodate streaming media traffic. This paper describes the architecture of a ultra-scalable IP switch and the first experiments with a prototypal implementation. The switch scalability is a consequence of it operating pipeline forwarding of packets, which also results in quality of service guarantees for UDP-based streaming applications, while preserving elastic TCP-based traffic as is, i.e., without affecting any existing applications based on "best- effort" services. Moreover, the prototype demonstrates the low complexity of pipeline forwarding implementation as the deployed network gear was realized from off-the-shelf components in only nine months through the design, implementation, and testing efforts of the authors

Hamiltonian Decompositions of Regular Topology Networks with Convergence Routing

This paper introduces new methods to construct multiple virtual rings for loss-free routing of non-reserved bursty data in high-speed environments such as ATM LANs. The routing algorithm on multiple virtual rings is convergence routing which combines the actual routing decision with the internal flow control state. Multiple virtual rings are obtained on the hypercube and the circulant networks such that each virtual ring is hamiltonian, and are mutually edge-disjoint. It is shown that multiple virtual rings improve (i) the bound on the length of routing, and (ii) the fault tolerance. On the circulant graphs, necessary and sufficient conditions for hamiltonian decomposition is established. On the hypercube, three algorithms are designed for an N-node hypercube with even dimension: (i) an O(N) time algorithm to find two edge-disjoint hamiltonian circuits, (ii) an O(N log N) time algorithm to find I01N hamiltonian circuits with only E ~ 0.1 common edges, and (iii) a recursive algorithm for the hamiltonian decomposition of the hypercube with dimension power of two. It is shown analytically, and verified by simulations on the circulants that with the d virtual ring embeddings, a bound of O( N / d) is established on the maximum length of routing

Application-oriented trust in distributed computing

Preserving integrity of applications being executed in remote machines is an open problem. Integrity requires that application code is not tampered with, prior to or during execution, by a rogue user or a malicious software agent. This paper presents a methodology to enforce runtime integrity of application code by means of an integritypreserving software component that is combined with the application. The software component is a trusted logic that can be replaced continuously from a remote location during run-time. For added assurance, the software component produces continuous sequence of proofs of its proper operation that are verified remotely

Counting is almost all you need

The immune memory repertoire encodes the history of present and past infections and immunological attributes of the individual. As such, multiple methods were proposed to use T-cell receptor (TCR) repertoires to detect disease history. We here show that the counting method outperforms two leading algorithms. We then show that the counting can be further improved using a novel attention model to weigh the different TCRs. The attention model is based on the projection of TCRs using a Variational AutoEncoder (VAE). Both counting and attention algorithms predict better than current leading algorithms whether the host had CMV and its HLA alleles. As an intermediate solution between the complex attention model and the very simple counting model, we propose a new Graph Convolutional Network approach that obtains the accuracy of the attention model and the simplicity of the counting model. The code for the models used in the paper is provided at: https://github.com/louzounlab/CountingIsAlmostAllYouNeed

The scientific payload of the Ultraviolet Transient Astronomy Satellite (ULTRASAT)

The Ultraviolet Transient Astronomy Satellite (ULTRASAT) is a space-borne near UV telescope with an unprecedented large field of view (200 sq. deg.). The mission, led by the Weizmann Institute of Science and the Israel Space Agency in collaboration with DESY (Helmholtz association, Germany) and NASA (USA), is fully funded and expected to be launched to a geostationary transfer orbit in Q2/3 of 2025. With a grasp 300 times larger than GALEX, the most sensitive UV satellite to date, ULTRASAT will revolutionize our understanding of the hot transient universe, as well as of flaring galactic sources. We describe the mission payload, the optical design and the choice of materials allowing us to achieve a point spread function of ~10arcsec across the FoV, and the detector assembly. We detail the mitigation techniques implemented to suppress out-of-band flux and reduce stray light, detector properties including measured quantum efficiency of scout (prototype) detectors, and expected performance (limiting magnitude) for various objects.Comment: Presented in the SPIE Astronomical Telescopes + Instrumentation 202

An Efficient Scheduling Algorithm for Time-Driven Switching Networks

In Time-driven Switching (TDS) networks with non-immediate forwarding (NIF) provides scheduling flexibility and consequently, reduces the blocking probability (blocking is defined to take place when transmission capacity is available, but without a feasible schedule). However, it has been shown that with NIF scheduling complexity may grow exponentially. Efficiently finding a schedule from an exponential set of potential schedules is the focus of this paper. The work first presents the mathematical formulation of the NIF scheduling problem, under a wide variety of networking requirements, then introduces an efficient (i.e., having at most polynomial complexity) search algorithm that guarantees to find at least one schedule whenever such a schedule exists. The novel algorithm uses "trellis" representations and the well-known survivor-based searching principle

Efficient Scheduling for Heterogeneous Fractional Lambda Switching Networks

Efficient scheduling for heterogeneous fractional lambda switching (FLS) networks is required but challenging. A heterogeneous network implies bandwidth mismatch between links of varied bit rates. Moreover, when non-immediate forwarding (NIF) is used in FLS, it increases the scheduling complexity exponentially, while decreasing the blocking probability. Thus, NIF scheduling presents a serious challenge for an algorithm to be used in a large heterogeneous FLS network. In this paper, an efficient scheduling algorithm that is combined with a flexible forwarding scheme is presented. The algorithm provides a full scheduling solution for an end-to-end request in heterogeneous FλS networks. Furthermore, the algorithm has linear complexity in single-channel networks and quadratic complexity in multiple-channel WDM networks

Overview of the MetaRing Architecture

The basic MetaRing architecture is a full-duplex ring providing fairness and spatial bandwidth reuse. Concurrent access and spatial bandwidth reuse enable simultaneous transmission over disjoint segments of the bidirectional ring. It therefore increases the potential throughput in each direction, by a factor of four or more. In this work, we overview the MetaRing principles: (1) Distributed global fairness algorithm, a simple and robust mechanism based on a single control signal (i.e., one bit of information) that regulates the access to the ring. (2) Protocol for service integration of: (i) synchronous or real-time tra c which is periodic and requires a connection set-up and which will have guaranteed bandwidth as well as bounded delay, and (ii) connectionless or asynchronous tra c with no real-time constraints that can use the remainder of the bandwidth. Integration is an important function for multi-media applications. (3) Protocol and requirements for multi-ring and dual-bus MetaRing networks. (4) Principles and requirements for interconnecting MetaRing with wide-area networks (WANs). We show that (i) the WAN-to-ring interconnection requires a separate queue for asynchronous tra c and relies on the use of the fairness mechanism for internal ow control, whereas (ii) the WAN-to-dual-bus con guration of the MetaRing network is simpler, since it does not require any bu ering and does not rely on a fairness mechanism for internal ow control, furthermore; it is fault tolerant and has better synchronous tra c performance

Yoram Ofek Synchrodyne, Inc. New York, NY 10463

In general topology networks, routing from one node to another over a tree embedded in the network is intuitively a good strategy, since it typically results in a route length of O(log n) links, being n the number of nodes in the network. Routing from one node to another over a ring embedded in the network would result in route length of O(n) links. However, in group (manyto -many) multicast, the overall number of links traversed by each packet, i.e. the networks elements on which resources must be possibly reserved, is typically O(N) for both tree and ring embedding, where N is the size of the group. This paper focuses on the tree versus ring embedding for real-time group multicast in which all packets should reach all other nodes in the group with a bounded end-to-end delay. In this work real-time properties are guaranteed by the deployment of time-driven priority in network nodes. In order to have a better understanding of the non-trivial problem of ring versus tree embedding, we c..