1,188 research outputs found
An End-to-End Performance Analysis for Service Chaining in a Virtualized Network
Future mobile networks supporting Internet of Things are expected to provide
both high throughput and low latency to user-specific services. One way to
overcome this challenge is to adopt Network Function Virtualization (NFV) and
Multi-access Edge Computing (MEC). Besides latency constraints, these services
may have strict function chaining requirements. The distribution of network
functions over different hosts and more flexible routing caused by service
function chaining raise new challenges for end-to-end performance analysis. In
this paper, as a first step, we analyze an end-to-end communications system
that consists of both MEC servers and a server at the core network hosting
different types of virtual network functions. We develop a queueing model for
the performance analysis of the system consisting of both processing and
transmission flows. We propose a method in order to derive analytical
expressions of the performance metrics of interest. Then, we show how to apply
the similar method to an extended larger system and derive a stochastic model
for such systems. We observe that the simulation and analytical results
coincide. By evaluating the system under different scenarios, we provide
insights for the decision making on traffic flow control and its impact on
critical performance metrics.Comment: 30 pages. arXiv admin note: substantial text overlap with
arXiv:1811.0233
Algorithms for advance bandwidth reservation in media production networks
Media production generally requires many geographically distributed actors (e.g., production houses, broadcasters, advertisers) to exchange huge amounts of raw video and audio data. Traditional distribution techniques, such as dedicated point-to-point optical links, are highly inefficient in terms of installation time and cost. To improve efficiency, shared media production networks that connect all involved actors over a large geographical area, are currently being deployed. The traffic in such networks is often predictable, as the timing and bandwidth requirements of data transfers are generally known hours or even days in advance. As such, the use of advance bandwidth reservation (AR) can greatly increase resource utilization and cost efficiency. In this paper, we propose an Integer Linear Programming formulation of the bandwidth scheduling problem, which takes into account the specific characteristics of media production networks, is presented. Two novel optimization algorithms based on this model are thoroughly evaluated and compared by means of in-depth simulation results
Optimal Orchestration of Virtual Network Functions
-The emergence of Network Functions Virtualization (NFV) is bringing a set of
novel algorithmic challenges in the operation of communication networks. NFV
introduces volatility in the management of network functions, which can be
dynamically orchestrated, i.e., placed, resized, etc. Virtual Network Functions
(VNFs) can belong to VNF chains, where nodes in a chain can serve multiple
demands coming from the network edges. In this paper, we formally define the
VNF placement and routing (VNF-PR) problem, proposing a versatile linear
programming formulation that is able to accommodate specific features and
constraints of NFV infrastructures, and that is substantially different from
existing virtual network embedding formulations in the state of the art. We
also design a math-heuristic able to scale with multiple objectives and large
instances. By extensive simulations, we draw conclusions on the trade-off
achievable between classical traffic engineering (TE) and NFV infrastructure
efficiency goals, evaluating both Internet access and Virtual Private Network
(VPN) demands. We do also quantitatively compare the performance of our VNF-PR
heuristic with the classical Virtual Network Embedding (VNE) approach proposed
for NFV orchestration, showing the computational differences, and how our
approach can provide a more stable and closer-to-optimum solution
Online Load Balancing for Network Functions Virtualization
Network Functions Virtualization (NFV) aims to support service providers to
deploy various services in a more agile and cost-effective way. However, the
softwarization and cloudification of network functions can result in severe
congestion and low network performance. In this paper, we propose a solution to
address this issue. We analyze and solve the online load balancing problem
using multipath routing in NFV to optimize network performance in response to
the dynamic changes of user demands. In particular, we first formulate the
optimization problem of load balancing as a mixed integer linear program for
achieving the optimal solution. We then develop the ORBIT algorithm that solves
the online load balancing problem. The performance guarantee of ORBIT is
analytically proved in comparison with the optimal offline solution. The
experiment results on real-world datasets show that ORBIT performs very well
for distributing traffic of each service demand across multipaths without
knowledge of future demands, especially under high-load conditions
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