Analysis of Matching Dynamics of PIM with Multiple Iterations in an Input-Buffered Packet Switch

Abstract Optical packet switching has gained lot of popularity in last a few years due to its advantages like, large speed, more bandwidth and very less crosstalk. But due to immature optical fabrication and designing technology OPS is still beyond reality. However, many of the optical components are commercialized and some of them are still in laboratory. Thus, for optical switches which are considered as future generation routers, many switch architectures are proposed by using different sets of optical components. This paper presents a detailed review of notable switch designs in past 20 years, and also presents a comprehensive literature survey of the notable papers related to optical packet switch designs.

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Hybrid buffer‐based optical packet switch with negative acknowledgment for multilevel data centers

Journal of Optical Communications ◽

10.1515/joc-2020-0060 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Sumit Chandra ◽

Shahnaz Fatima ◽

Raghuraj Singh Suryavanshi

Keyword(s):

Data Centers ◽

Web Applications ◽

Optical Switch ◽

Contention Resolution ◽

Multilevel Data ◽

All Optical ◽

Optical Buffering ◽

Different Types ◽

Packet Switch ◽

Novel Design

AbstractIn the present scenario, data centers serve many functionalities like storage, transfer of data, supporting web applications, etc. In data centers, various levels of hierarchy different types of switches are required; therefore, multifunctional data centers are desired. This paper discusses a novel design for optical switch which can be placed at various levels of hierarchy. In the proposed design, multifunctionality contention resolution schemes which consider electronic and optical buffering and all-optical negative acknowledgment (AO-NACK) are considered. In buffering technologies, contending packets are stored in either in electronic RAM or in fiber delay lines. In case of the AO-NACK scheme, contending packets are blocked, and a negative acknowledgment is sent back to the transmitting node and blocked packets are retransmitted. For various considered schemes, Monte Carlo simulation have been performed, results in terms of packet loss probability are presented, and it has been found that the performance of optical buffering is much superior to electronic buffering and AO-NACK schemes. It is found that, in the AO-NACK scheme, the numbers of retransmitted packets due to contention blocking are 33,304 which can be reduced to 7, by using a small amount of buffer at each node.

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Load-Optimization in Reconfigurable Networks

ACM SIGMETRICS Performance Evaluation Review ◽

10.1145/3453953.3453962 ◽

2021 ◽

Vol 48 (3) ◽

pp. 39-44 ◽

Cited By ~ 1

Author(s):

Wenkai Dai ◽

Klaus-Tycho Foerster ◽

David Fuchssteiner ◽

Stefan Schmid

Keyword(s):

Data Centers ◽

Algorithmic Problem ◽

Reconfigurable Networks ◽

Load Optimization ◽

Clos Networks ◽

Optical Circuit ◽

Tree Topologies ◽

Packet Switch ◽

Routing Policies

Emerging reconfigurable data centers introduce the unprecedented flexibility in how the physical layer can be programmed to adapt to current traffic demands. These reconfigurable topologies are commonly hybrid, consisting of static and reconfigurable links, enabled by e.g. an Optical Circuit Switch (OCS) connected to top-of-rack switches in Clos networks. Even though prior work has showcased the practical benefits of hybrid networks, several crucial performance aspects are not well understood. In this paper, we study the algorithmic problem of how to jointly optimize topology and routing in reconfigurable data centers with a known traffic matrix, in order to optimize a most fundamental metric, maximum link load. We chart the corresponding algorithmic landscape by investigating both un-/splittable flows and (non-)segregated routing policies. We moreover prove that the problem is not submodular for all these routing policies, even in multi-layer trees, where a topological complexity classification of the problem reveals that already trees of depth two are intractable. However, networks that can be abstracted by a single packet switch (e.g., nonblocking Fat-Tree topologies) can be optimized efficiently, and we present optimal polynomialtime algorithms accordingly. We complement our theoretical results with trace-driven simulation studies, where our algorithms can significantly improve the network load in comparison to the state of the art.

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