147 research outputs found
A Reliability Study of Parallelized VNF Chaining
In this paper, we study end-to-end service reliability in Data Center
Networks (DCN) with flow and Service Function Chains (SFCs) parallelism. In our
approach, we consider large flows to i) be split into multiple parallel smaller
sub-flows; ii) SFC along with their VNFs are replicated into at least as many
VNF instances as there are sub-flows, resulting in parallel sub-SFCs; and iii)
all sub-flows are distributed over multiple shortest paths and processed in
parallel by parallel sub-SFCs. We study service reliability as a function of
flow and SFC parallelism and placement of parallel active and backup sub-SFCs
within DCN. Based on the probability theory and by considering both server and
VNF failures, we analytically derive for each studied VNF placement method the
probability that all sub-flows can be successfully processed by the
parallelized SFC without service interruption. We evaluate the amount of backup
VNFs required to protect the parallelized SFC with a certain level of service
reliability. The results show that the proposed flow and SFC parallelism in DCN
can significantly increase end-to-end service reliability, while reducing the
amount of backup VNFs required, as compared to traditional SFCs with serial
traffic flows
A Novel Network Coded Parallel Transmission Framework for High-Speed Ethernet
Parallel transmission, as defined in high-speed Ethernet standards, enables
to use less expensive optoelectronics and offers backwards compatibility with
legacy Optical Transport Network (OTN) infrastructure. However, optimal
parallel transmission does not scale to large networks, as it requires
computationally expensive multipath routing algorithms to minimize differential
delay, and thus the required buffer size, optimize traffic splitting ratio, and
ensure frame synchronization. In this paper, we propose a novel framework for
high-speed Ethernet, which we refer to as network coded parallel transmission,
capable of effective buffer management and frame synchronization without the
need for complex multipath algorithms in the OTN layer. We show that using
network coding can reduce the delay caused by packet reordering at the
receiver, thus requiring a smaller overall buffer size, while improving the
network throughput. We design the framework in full compliance with high-speed
Ethernet standards specified in IEEE802.3ba and present solutions for network
encoding, data structure of coded parallel transmission, buffer management and
decoding at the receiver side. The proposed network coded parallel transmission
framework is simple to implement and represents a potential major breakthrough
in the system design of future high-speed Ethernet.Comment: 6 pages, 8 figures, Submitted to Globecom201
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