Carl J. Nuzman

1296-port MEMS transparent optical crossconnect with 2.07 petabit/s switch capacity

A 1296-port MEMS transparent optical crossconnect with 5.1dB/spl plusmn/1.1dB insertion loss at 1550 nm is reported. Measured worst-case optical crosstalk in a fabric was n38 dB and nominal switching rise/fall times were 5 ms. A 2.07 petabit/s switch capacity was verified upon cross-connecting a forty-channel by 40 Gb/s DWDM data stream through a prototype fabric.

The ITU-T's new g.vector standard proliferates 100 mb/s dsl

This article explores the recently issued ITUT G.vector (G.993.5) that allows expanded use of 100 Mb/s DSL. A tutorial description on G.vectors crosstalk noise reduction methods leads to specific projections and measurements of expanded DSL 100 Mb/s reach. A discussion on dynamic maintenance to enhance G.vectors practical application then concludes this article.

A compound model for TCP connection arrivals for LAN and WAN applications

We propose a two level model for TCP connection arrivals in local area networks. The first level are user sessions whose arrival is time-varying Poisson. The second level are connections within a user session. Their number and mean interarrival times are independent and biPareto across user sessions. The interarrivals within a user session are Weibull, and across all users are correlated Weibull. Our model has a small number of parameters which are inferred from real traffic collected at a firewall. We show that traffic synthesized with our model closely matches the original data. We extend this approach to a general model involving shot noise and show it is asymptotically consistent with more common fractal models used in data networks. Finally, we show that this model extends to the wide area network applications without alteration and it predicts smoothing of wide area network traffic profiles due to spatial aggregation, which we observe experimentally by synthetically creating a large aggregate TCP load.

Optical switch dimensioning and the classical occupancy problem

Results for optical switch dimensioning are obtained by analysing an urn occupancy problem in which a random number of balls is used. This analysis is applied to a high speed bufferless optical switch which uses tuneable wavelength converters to resolve contention between packets at the output fibres. Under symmetric packet routing the urn problem reduces to the classical occupancy problem. Since the problem is large scale and the loss probabilities are small, exact analysis by combinatorial methods is problematic. As an alternative, we outline a large deviations approximation which may be generalised in various ways. Copyright

Time-Domain Wavelength Interleaved Networking with Wavelength Reuse

Time-domain Wavelength Interleaved Networking (TWIN) is a cost-effective network architecture that can provide fine-grained, flexible connectivity using passive optics in internal nodes. Each wavelength is dedicated to carry traffic to a single node. We introduce TWIN with wavelength reuse (TWIN-WR), an extension of TWIN that allows the number of nodes to exceed the number of wavelengths. We formulate an associated design problem, decompose it into subproblems, and provide algorithms for solving the subproblems. We experimentally demonstrate that our algorithms come close to upper bounds over a wide range of parameters, and show that the resulting designs are robust in the face of traffic variability and uncertainty. Analysis and experiment show that high efficiency can be maintained as long as the number of nodes does not exceed the square of the number of wavelengths, in principle allowing a network with thousands of nodes using only one hundred wavelengths.

Effects of modularity and connectivity on OADM deployment in ring networks

For a class of optical add/drop multiplexers, we empirically study the effects of port modularity and connectivity on device deployment in ring networks. Designs with greater connectivity and smaller modules allow fewer devices to be deployed.

A compound model for TCP connection arrivals: Empirical study within a general framework

We propose a two level model for TCP connection arrivals in local area networks. The first level are user sessions whose arrival is time-varying Poisson. The second level are connections within a user session. Their number and mean interrival are independent and biPareto across user session. The interarrivals within a user session are Weibull, and across all users are correlated Weibull. Our model has a small number of parameters which are inferred from real traffic colected at a firewall. We show that traffic synthesized with our model closely characterizes the original data. We extend this approach to a general model involving shot noise that is shown to be asymptotically consistent with more common fractal models used in data networks.