44,689 research outputs found
Joint Energy Efficient and QoS-aware Path Allocation and VNF Placement for Service Function Chaining
Service Function Chaining (SFC) allows the forwarding of a traffic flow along
a chain of Virtual Network Functions (VNFs, e.g., IDS, firewall, and NAT).
Software Defined Networking (SDN) solutions can be used to support SFC reducing
the management complexity and the operational costs. One of the most critical
issues for the service and network providers is the reduction of energy
consumption, which should be achieved without impact to the quality of
services. In this paper, we propose a novel resource (re)allocation
architecture which enables energy-aware SFC for SDN-based networks. To this
end, we model the problems of VNF placement, allocation of VNFs to flows, and
flow routing as optimization problems. Thereafter, heuristic algorithms are
proposed for the different optimization problems, in order find near-optimal
solutions in acceptable times. The performance of the proposed algorithms are
numerically evaluated over a real-world topology and various network traffic
patterns. The results confirm that the proposed heuristic algorithms provide
near optimal solutions while their execution time is applicable for real-life
networks.Comment: Extended version of submitted paper - v7 - July 201
Distributed Algorithms for Spectrum Allocation, Power Control, Routing, and Congestion Control in Wireless Networks
We develop distributed algorithms to allocate resources in multi-hop wireless
networks with the aim of minimizing total cost. In order to observe the
fundamental duplexing constraint that co-located transmitters and receivers
cannot operate simultaneously on the same frequency band, we first devise a
spectrum allocation scheme that divides the whole spectrum into multiple
sub-bands and activates conflict-free links on each sub-band. We show that the
minimum number of required sub-bands grows asymptotically at a logarithmic rate
with the chromatic number of network connectivity graph. A simple distributed
and asynchronous algorithm is developed to feasibly activate links on the
available sub-bands. Given a feasible spectrum allocation, we then design
node-based distributed algorithms for optimally controlling the transmission
powers on active links for each sub-band, jointly with traffic routes and user
input rates in response to channel states and traffic demands. We show that
under specified conditions, the algorithms asymptotically converge to the
optimal operating point.Comment: 14 pages, 5 figures, submitted to IEEE/ACM Transactions on Networkin
A Fair and Efficient Packet Scheduling Scheme for IEEE 802.16 Broadband Wireless Access Systems
This paper proposes a fair and efficient QoS scheduling scheme for IEEE
802.16 BWA systems that satisfies both throughput and delay guarantee to
various real and non-real time applications. The proposed QoS scheduling scheme
is compared with an existing QoS scheduling scheme proposed in literature in
recent past. Simulation results show that the proposed scheduling scheme can
provide a tight QoS guarantee in terms of delay, delay violation rate and
throughput for all types of traffic as defined in the WiMAX standard, thereby
maintaining the fairness and helps to eliminate starvation of lower priority
class services. Bandwidth utilization of the system and fairness index of the
resources are also encountered to validate the QoS provided by our proposed
scheduling scheme
Application-Oriented Flow Control: Fundamentals, Algorithms and Fairness
This paper is concerned with flow control and resource allocation problems in computer networks in which real-time applications may have hard quality of service (QoS) requirements. Recent optimal flow control approaches are unable to deal with these problems since QoS utility functions generally do not satisfy the strict concavity condition in real-time applications. For elastic traffic, we show that bandwidth allocations using the existing optimal flow control strategy can be quite unfair. If we consider different QoS requirements among network users, it may be undesirable to allocate bandwidth simply according to the traditional max-min fairness or proportional fairness. Instead, a network should have the ability to allocate bandwidth resources to various users, addressing their real utility requirements. For these reasons, this paper proposes a new distributed flow control algorithm for multiservice networks, where the application's utility is only assumed to be continuously increasing over the available bandwidth. In this, we show that the algorithm converges, and that at convergence, the utility achieved by each application is well balanced in a proportionally (or max-min) fair manner
Traffic Engineering with Segment Routing: SDN-based Architectural Design and Open Source Implementation
Traffic Engineering (TE) in IP carrier networks is one of the functions that
can benefit from the Software Defined Networking paradigm. By logically
centralizing the control of the network, it is possible to "program" per-flow
routing based on TE goals. Traditional per-flow routing requires a direct
interaction between the SDN controller and each node that is involved in the
traffic paths. Depending on the granularity and on the temporal properties of
the flows, this can lead to scalability issues for the amount of routing state
that needs to be maintained in core network nodes and for the required
configuration traffic. On the other hand, Segment Routing (SR) is an emerging
approach to routing that may simplify the route enforcement delegating all the
configuration and per-flow state at the border of the network. In this work we
propose an architecture that integrates the SDN paradigm with SR-based TE, for
which we have provided an open source reference implementation. We have
designed and implemented a simple TE/SR heuristic for flow allocation and we
show and discuss experimental results.Comment: Extended version of poster paper accepted for EWSDN 2015 (version v4
- December 2015
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