Elastic network functions: opportunities and challenges

Abstract

ocio-economic drivers, progress in information technologies, tumbling switching and computer hardware costs, and availability of open source software solutions, are creating the conditions for a change of paradigm in designing and operating telecommunication networks and service infrastructures. Network function virtualization (NFV) [1] by the European Telecommunications Standards Institute (ETSI), and software defined networking (SDN) [2] by the Open Networking Forum seem to be key technology enablers in the direction of meeting requirements such as cost reductions and new business models. NFV, on the one hand, targets at virtualizing servers and appliances that provide network functions. One of NFVs value propositions is cost optimization with the use of commercial off the shelf hardware to reduce capital expenditure. This, together with increased operational efficiency, is expected to also reduce operational expenditure. Operational efficiency is achieved by the automation of commission, configuration, resource management, etc., for even an order of magnitude higher number of managed elements than before. SDN, on the other hand, targets at breaking the vertical integration of network data and control planes to introduce (logically centralized) control plane programmability for novel networking virtualization (abstraction), simplified network (re)configuration, and policy enforcement.Today, all these promises are not yet realized. A typical example is the device located at the edge of carrier networks.Here fixed network operators require broadband network gateway (BNG) functionality for customer centric processes such as authentication, policing, etc. Technically, those gateways are physical devices hosting special network services, or software combining network control plane and data plane aspects for fulfilling the processes, sometimes even supported by hardware acceleration. Given the fact that the broadband network gateway is operated like an appliance, it is difficult to add and evolve the service offering. For example, adding a parental control function or an intrusion detection system (IDS) for a certain customer is rather cumbersome. Today, this would require the instantiation of a separate IDS application, forwarding enforcement between the network gateway and the intrusion detection, and a policy interface to configure blocking of malicious traffic. Dynamism in changing control parameters such as addresses adds additional management complexity.The NFV framework [3] promises to remedy the problems of flexible service creation by managing and orchestrating softwarized network functions into telecommunication data centers. However, considering the full lifecycle of flexible network services, e.g. fulfillment, assurance, and billing [4], one must look beyond the fulfillment phase and see that flexibility is also ensured during assurance (operation) phase.We investigate how network services can scale up/down or scale in/out to offer real elastic, pay as use services. Our main contribution is the analysis o...

Introducing Development Features for Virtualized Network Services

“…The focus shifts to telco-grade NFV, beyond cloud provider functionality as mentioned earlier. Both UNIFY [3] and SONATA [4] define a MANO architecture that allows custom, service-specific control functionality, like scaling, configuration and placement. UNIFY has a SP-DevOps toolkit [6] for post-deployment troubleshooting and SONATA provides a pre-deployment tool-chain to describe, validate and package complete service chains [13].…”

“…UNIFY has a SP-DevOps toolkit [6] for post-deployment troubleshooting and SONATA provides a pre-deployment tool-chain to describe, validate and package complete service chains [13]. OSM 3…”

“…Implementing custom lifecycle events can be done by e.g. Cloudify Lifecycle Events, AWS Lifecycle Hooks, Azure Functions webhooks, and service control using Google Cloud App Engine 3. Open-Source-MANO (OSM): https://osm.etsi.org/ (Accessed on 11 Sept 2017)4 The Open Network Automation Platform (ONAP): https://www.onap.org/ (Accessed on 11 Sept 2017)5 Open-Baton: Open-Source MANO framework: http://openbaton.github.io/ (Accessed on 11 Sept 2017)…”

DevOps for network function virtualisation: an architectural approach

“…In a network service context, this recursive structure can either be a specific part of a network service or a repeated part of the deployment platform. Although different challenges can be thought of, the general idea of reusing existing patterns could reduce complexity and even add more flexible possibilities for extending the service . In Figure , recursive orchestration is shown as a SONATA service platform delegating (part of) the requested service to another instance of a SONATA platform using a dedicated infrastructure adaptor.Reclusiveness also leads to an easier management of scalability.…”

An OpenFlow-based Dynamic Service Chaining Approach for Hybrid Network Functions Virtualization

“…It means that one or more virtualized network functions (VNFs) together with the traditional middle boxes can be promptly established for a complex enterprise network. Under this situation, one of challenges is how to provide the routing path decision (10)- (11) , service ordering, and the communications between switches and middle boxes. In this paper, we propose a framework for building an OpenFlow-based dynamic services chaining mechanism and present a routing path management for a hybrid NFV environment.…”