6,331 research outputs found
Architecture, design, and modeling of the OPSnet asynchronous optical packet switching node
An all-optical packet-switched network supporting multiple services represents a long-term goal for network operators and service providers alike. The EPSRC-funded OPSnet project partnership addresses this issue from device through to network architecture perspectives with the key objective of the design, development, and demonstration of a fully operational asynchronous optical packet switch (OPS) suitable for 100 Gb/s dense-wavelength-division multiplexing (DWDM) operation. The OPS is built around a novel buffer and control architecture that has been shown to be highly flexible and to offer the promise of fair and consistent packet delivery at high load conditions with full support for quality of service (QoS) based on differentiated services over generalized multiprotocol label switching
Multiclass scheduling algorithms for the DAVID metro network
AbstractâThe data and voice integration over dense wavelength-division-multiplexing (DAVID) project proposes a metro network architecture based on several wavelength-division-multiplexing (WDM) rings interconnected via a bufferless optical switch called Hub. The Hub provides a programmable interconnection among rings on the basis of the outcome of a scheduling algorithm. Nodes connected to rings groom traffic from Internet protocol routers and Ethernet switches and share ring resources. In this paper, we address the problem of designing efficient centralized scheduling algorithms for supporting multiclass traffic services in the DAVID metro network. Two traffic classes are considered: a best-effort class, and a high-priority class with bandwidth guarantees. We define the multiclass scheduling problem at the Hub considering two different node architectures: a simpler one that relies on a complete separation between transmission and reception resources (i.e., WDM channels) and a more complex one in which nodes fully share transmission and reception channels using an erasure stage to drop received packets, thereby allowing wavelength reuse. We propose both optimum and heuristic solutions, and evaluate their performance by simulation, showing that heuristic solutions exhibit a behavior very close to the optimum solution. Index TermsâData and voice integration over dense wavelength-division multiplexing (DAVID), metropolitan area network, multiclass scheduling, optical ring, wavelength-division multiplexing (WDM). I
Traffic Engineering in G-MPLS networks with QoS guarantees
In this paper a new Traffic Engineering (TE) scheme to efficiently route sub-wavelength requests with different QoS requirements is proposed for G-MPLS networks. In most previous studies on TE based on dynamic traffic grooming, the objectives were to minimize the rejection probability by respecting the constraints of the optical node architecture, but without considering service differentiation. In practice, some high-priority (HP) connections can instead be characterized by specific constraints on the maximum tolerable end-to-end delay and packet-loss ratio. The proposed solution consists of a distributed two-stage scheme: each time a new request arrives, an on-line dynamic grooming scheme finds a route which fulfills the QoS requirements. If a HP request is blocked at the ingress router, a preemption algorithm is executed locally in order to create room for this traffic. The proposed preemption mechanism minimizes the network disruption, both in term of number of rerouted low-priority connections and new set-up lightpaths, and the signaling complexity. Extensive simulation experiments are performed to demonstrate the efficiency of our scheme
Design of a Hybrid Modular Switch
Network Function Virtualization (NFV) shed new light for the design,
deployment, and management of cloud networks. Many network functions such as
firewalls, load balancers, and intrusion detection systems can be virtualized
by servers. However, network operators often have to sacrifice programmability
in order to achieve high throughput, especially at networks' edge where complex
network functions are required.
Here, we design, implement, and evaluate Hybrid Modular Switch (HyMoS). The
hybrid hardware/software switch is designed to meet requirements for modern-day
NFV applications in providing high-throughput, with a high degree of
programmability. HyMoS utilizes P4-compatible Network Interface Cards (NICs),
PCI Express interface and CPU to act as line cards, switch fabric, and fabric
controller respectively. In our implementation of HyMos, PCI Express interface
is turned into a non-blocking switch fabric with a throughput of hundreds of
Gigabits per second.
Compared to existing NFV infrastructure, HyMoS offers modularity in hardware
and software as well as a higher degree of programmability by supporting a
superset of P4 language
Breaking the Legend: Maxmin Fairness notion is no longer effective
In this paper we analytically propose an alternative approach to achieve
better fairness in scheduling mechanisms which could provide better quality of
service particularly for real time application. Our proposal oppose the
allocation of the bandwidth which adopted by all previous scheduling mechanism.
It rather adopt the opposition approach be proposing the notion of
Maxmin-charge which fairly distribute the congestion. Furthermore, analytical
proposition of novel mechanism named as Just Queueing is been demonstrated.Comment: 8 Page
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