1,720,993 research outputs found
Analysis and Simulation of a Parallel Packet Switch for Satellite On-board Switching
Full text linkIn this paper we consider a packet switching system composed of X parallel switching planes
operating independently and at a speed lower than the input lines. Arriving traffic is segmented into
fixed length cells, then each cell is sent to one of the X planes, where it is switched to the correct
output port and finally recombined with the other cells, coming from other planes, to reconstruct the
original packet. This architecture, originally proposed by Iyer and McKeown [1], is referred to as a
Parallel Packet Switch (PPS) and allows to design a switching fabric operating at a fraction of the line
rate R. A PPS, with planes operating at rate r, must have at least k=R/r planes to avoid systematic
packet losses. In [1] it was proved that a PPS can emulate the behavior of an Output Queue Switch
(OQS) with the same buffering capabilities and the same number of ports. However, the centralized
scheduling algorithm required to achieve this result can not be easily implemented in hardware, due to
its complexity.
In this paper we propose a Redundant Parallel Packet Switch (RePPS), i.e. a PPS with more than k
planes, with a distributed scheduling algorithm, and multiplexing/demultiplexing stages without
coordination buffers, which is a fair trade-off between performance and complexity. In particular we
show that the minimum number n = X - k of redundant planes required to emulate an OQS with FIFO
policy under any incoming traffic type is n = k2-2k+1. The distributed scheduling algorithm, which is the
key component of the proposed switch, is presented and its performance, analyzed thru simulation, is
discussed for a realistic fabric with a limited number of redundant planes. The results so far obtained
suggest a possible application of this architecture for satellite on-board packet switches
MOON: a New Overlay Network Architecture for Mobility and QoS Support
Full text linkThe continuously increasing diffusion of mobile devices
such as laptops, PDAs and smartphones, all equipped with
enhanced functionalities, has led to numerous studies about
mobility and to the definition of new network architectures
capable to support it.
Problems related to mobility have been addressed mostly
operating on the network or transport layers of the Internet
protocol stack. As a result, most of these solutions generally
require modifying the TCP and/or the IP protocol. Although this
approach is well suited to handle mobility, it lacks in
compatibility with the Internet Protocol Suite.
This consideration led us to study a fully TCP compatible and
flexible approach we dubbed MOON, for MObile Overlay
Network. This network architecture is currently under design at
LIPAR, the Internet, Protocols and Network Architecture Lab of
Politecnico di Torino
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