Service Function Graph Design And Embedding In Next Generation Internet

Network Function Virtualization (NFV) and Software Defined Networking (SDN) are viewed as the techniques to design, deploy and manage future Internet services. NFV provides an effective way to decouple network functions from the proprietary hardware, allowing the network providers to implement network functions as virtual machines running on standard servers. In the NFV environment, an NFV service request is provisioned in the form of a Service Function Graph (SFG). The SFG defines the exact set of actions or Virtual Network Functions (VNFs) that the data stream from the service request is subjected to. These actions or VNFs need to be embedded onto specific physical (substrate) networks to provide network services for end users. Similarly, SDN decouples the control plane from network devices such as routers and switches. The network control management is performed via an open interface and the underlying infrastructure turned into simple programmable forwarding devices. NFV and SDN are complementary to each other. Specifically, similar to running network functions on general purpose servers, SDN control plane can be implemented as pure software running on industry standard hardware. Moreover, automation and virtualization provide both NFV and SDN the tools to achieve their respective goals. In this dissertation, we motivate the importance of service function graph design, and we focus our attention on the problem of embedding network service requests. Throughout the dissertation, we highlight the unique properties of the service requests and investigate how to efficiently design and embed an SFG for a service request onto substrate network. We address variations of the embedding service requests such as dependence awareness and branch awareness in service function graph design and embedding. We propose novel algorithms to design and embed service requests with dependence and branch awareness. We also provide the intuition behind our proposed schemes and analyze our suggested approaches over multiple metrics against other embedding techniques

Can open-source projects (re-) shape the SDN/NFV-driven telecommunication market?

Telecom network operators face rapidly changing business needs. Due to their dependence on long product cycles they lack the ability to quickly respond to changing user demands. To spur innovation and stay competitive, network operators are investigating technological solutions with a proven track record in other application domains such as open source software projects. Open source software enables parties to learn, use, or contribute to technology from which they were previously excluded. OSS has reshaped many application areas including the landscape of operating systems and consumer software. The paradigmshift in telecommunication systems towards Software-Defined Networking introduces possibilities to benefit from open source projects. Implementing the control part of networks in software enables speedier adaption and innovation, and less dependencies on legacy protocols or algorithms hard-coded in the control part of network devices. The recently proposed concept of Network Function Virtualization pushes the softwarization of telecommunication functionalities even further down to the data plane. Within the NFV paradigm, functionality which was previously reserved for dedicated hardware implementations can now be implemented in software and deployed on generic Commercial Off-The Shelf (COTS) hardware. This paper provides an overview of existing open source initiatives for SDN/NFV-based network architectures, involving infrastructure to orchestration-related functionality. It situates them in a business process context and identifies the pros and cons for the market in general, as well as for individual actors

Network Function Virtualization Service Delivery In Future Internet

This dissertation investigates the Network Function Virtualization (NFV) service delivery problems in the future Internet. With the emerging Internet of everything, 5G communication and multi-access edge computing techniques, tremendous end-user devices are connected to the Internet. The massive quantity of end-user devices facilitates various services between the end-user devices and the cloud/edge servers. To improve the service quality and agility, NFV is applied. In NFV, the customer\u27s data from these services will go through multiple Service Functions (SFs) for processing or analysis. Unlike traditional point-to-point data transmission, a particular set of SFs and customized service requirements are needed to be applied to the customer\u27s traffic flow, which makes the traditional point-to-point data transmission methods not directly used. As the traditional point-to-point data transmission methods cannot be directly applied, there should be a body of novel mechanisms that effectively deliver the NFV services with customized~requirements. As a result, this dissertation proposes a series of mechanisms for delivering NFV services with diverse requirements. First, we study how to deliver the traditional NFV service with a provable boundary in unique function networks. Secondly, considering both forward and backward traffic, we investigate how to effectively deliver the NFV service when the SFs required in forward and backward traffic is not the same. Thirdly, we investigate how to efficiently deliver the NFV service when the required SFs have specific executing order constraints. We also provide detailed analysis and discussion for proposed mechanisms and validate their performance via extensive simulations. The results demonstrate that the proposed mechanisms can efficiently and effectively deliver the NFV services under different requirements and networking conditions. At last, we also propose two future research topics for further investigation. The first topic focuses on parallelism-aware service function chaining and embedding. The second topic investigates the survivability of NFV services

Dynamic Prioritization and Adaptive Scheduling using Deep Deterministic Policy Gradient for Deploying Microservice-based VNFs

The Network Function Virtualization (NFV)-Resource Allocation (RA) problem is NP-Hard. Traditional deployment methods revealed the existence of a starvation problem, which the researchers failed to recognize. Basically, starvation here, means the longer waiting times and eventual rejection of low-priority services due to a 'time out'. The contribution of this work is threefold: a) explain the existence of the starvation problem in the existing methods and their drawbacks, b) introduce 'Adaptive Scheduling' (AdSch) which is an 'intelligent scheduling' scheme using a three-factor approach (priority, threshold waiting time, and reliability), which proves to be more reasonable than traditional methods solely based on priority, and c) a 'Dynamic Prioritization' (DyPr), allocation method is also proposed for unseen services and the importance of macro- and micro-level priority. We presented a zero-touch solution using Deep Deterministic Policy Gradient (DDPG) for adaptive scheduling and an online-Ridge Regression (RR) model for dynamic prioritization. The DDPG successfully identified the 'Beneficial and Starving' services, efficiently deploying twice as many low-priority services as others, reducing the starvation problem. Our online-RR model learns the pattern in less than 100 transitions, and the prediction model has an accuracy rate of more than 80%

Arbitration Among Vertical Services

A 5G network provides several service types, tailored to specific needs such as high bandwidth or low latency. On top of these communication services, verticals are enabled to deploy their own vertical services. These vertical service instances compete for the resources of the underlying common infrastructure. We present a resource arbitration approach that allows to handle such resource conflicts on a high level and to provide guidance to lowerlevel orchestration components.This work has been partially funded by the EU H2020 5GTransformer Project (grant no. 761536)

CoShare: An Efficient Approach for Redundancy Allocation in NFV

An appealing feature of Network Function Virtualization (NFV) is that in an NFV-based network, a network function (NF) instance may be placed at any node. On the one hand this offers great flexibility in allocation of redundant instances, but on the other hand it makes the allocation a unique and difficult challenge. One particular concern is that there is inherent correlation among nodes due to the structure of the network, thus requiring special care in this allocation. To this aim, our novel approach, called CoShare, is proposed. Firstly, its design takes into consideration the effect of network structural dependency, which might result in the unavailability of nodes of a network after failure of a node. Secondly, to efficiently make use of resources, CoShare proposes the idea of shared reservation, where multiple flows may be allowed to share the same reserved backup capacity at an NF instance. Furthermore, CoShare factors in the heterogeneity in nodes, NF instances and availability requirements of flows in the design. The results from a number of experiments conducted using realistic network topologies show that the integration of structural dependency allows meeting availability requirements for more flows compared to a baseline approach. Specifically, CoShare is able to meet diverse availability requirements in a resource-efficient manner, requiring, e.g., up to 85% in some studied cases, less resource overbuild than the baseline approach that uses the idea of dedicated reservation commonly adopted for redundancy allocation in NFV

Multicast Aware Virtual Network Embedding in Software Defined Networks

The Software Defined Networking (SDN) provides not only a higher level abstraction of lower level functionalities, but also flexibility to create new multicast framework. SDN decouples the low level network elements (forwarding/data plane) from the control/management layer (control plane), where a centralized controller can access and modify the configuration of each distributed network element. The centralized framework allows to develop more network functionalities that can not be easily achieved in the traditional network architecture. Similarly, Network Function Virtualization (NFV) enables the decoupling of network services from the underlying hardware infrastructure to allow the same Substrate (Physical) Network (SN) shared by multiple Virtual Network (VN) requests. With the network virtualization, the process of mapping virtual nodes and links onto a shared SN while satisfying the computing and bandwidth constraints is referred to as Virtual Network Embedding (VNE), an NP-Hard problem. The VNE problem has drawn a lot of attention from the research community. In this dissertation, we motivate the importance of characterizing the mode of communication in VN requests, and we focus our attention on the problem of embedding VNs with one-to-many (multicast) communication mode. Throughout the dissertation, we highlight the unique properties of multicast VNs and explore how to efficiently map a given Virtual Multicast Tree/Network (VMT) request onto a substrate IP Network or Elastic Optical Networks (EONs). The major objective of this dissertation is to study how to efficiently embed (i) a given virtual request in IP or optical networks in the form of a multicast tree while minimizing the resource usage and avoiding the redundant multicast tranmission, (ii) a given virtual request in optical networks while minimizing the resource usage and satisfying the fanout limitation on the multicast transmission. Another important contribution of this dissertation is how to efficiently map Service Function Chain (SFC) based virtual multicast request without prior constructed SFC while minimizing the resource usage and satisfying the SFC on the multicast transmission

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