IEEE ComSoc CTN Special Issue on Software Defined Networks & Virtualization Trends in Communications

CTN Issue: August 2014

Elena Neira, CTN Editor in Chief & Director of Online Content, IEEE ComSoc Board of Governors


Anywhere you look in the Communications Technology Industry – mobile networks, content delivery, home connectivity, wireless, enterprise, IoT, data centers, cloud computing and backbone networks – you see and hear about “Software-ization” as one of the most important transformational forces underway in the industry. This trend is most commonly refereed as Software Defined Networks (SDN) and network Virtualization/Network Function Virtualization (NFV).

This special issue of IEEECTN examines how this pervasive force could transform network computing platforms and network architecture. It also discusses how SDN and NFV are changing the skill set and the expertise network engineers will need to design, plan and operate the networks of the future. In particular, the articles from the IEEE ComSoc Digital Library highlighted in this issue help frame the scope of SDN and virtualization (NFV). They show how network architecture and network protocols are evolving due to these trends, and present technical realizations from major open source projects.

The first article, “Interfaces, Attributes, and Use Cases: A Compass for SDN”, introduces SDN and virtualization (NFV) in communication networks. It covers the scope, high level architecture, APIs, and a list of critical features such as programmability and modularity. It also includes a list of use cases where this technology might be applied: Cloud Orchestration, Load Balancing, Routing &Forwarding, Network Management, and Application Awareness.

The second article, “Network Virtualization and Software Defined Networking for Cloud Computing: A Survey”, looks at virtualization of the network functions. It takes an Internet/Layer 3 (Network Layer) centric approach, and makes the following points. First, cloud computing is the result of advances in virtualization in computing, storage, and networking. Second, networking virtualization standards are under development by standards groups such as IEEE, IETF, and ETSI/3GPP. Third, key innovations disrupting current designs and products are: separation of the control and data planes, centralization of control, programmability, and standard southbound, northbound, and east-west APIs. Finally, OpenFlow is the standard adopted by a large number of industry players to realize the southbound API being defined by the Open Networking Forum (ONF). After several pages of surveying these four topics, the article gives an example of a new network application, OpenAND that enables partitioning and delivery in a multi-cloud environment.

The third and lastarticle, “Are We Ready for SDN? Implementation Challenges for Software-Defined Networks”, has recently been part of the IEEE ComSoc list of the ten most popular articles. It addresses the question whether SDN is ready to support multi-service operator networks.  SDN and virtualization promise operators better tools to cope with the increasing traffic demands. They allow a more flexible network management (easily adaptable to software upgrades), and better resource utilization by lowering both Capital Expenditure (CAPEX) and Operating Expenditure (OPEX). Other potential benefit is that SDN and NFV would require less specialized hardware. This is due to the elasticity of configuring new services in general purpose platforms, running tests and production on the same infrastructure, and enablement of Network as a Service (NaaS). The article provides clues on how carrier-grade infrastructure, functions and services such as IP support (ENUM, DNS, AAA), policy/charging control (PCRF, PCEF, etc.), application servers and such can be virtualized.  Finally one section worth highlighting is one where the authors address the question how can a programmable switch be achieved?

If you want to learn more and/or be part of SDN and NFV activities in IEEE ComSoc, here are someaditional resources…

  • Publish your own SDN/NFV article with IEEE responding to the IEEE Transactions on Network and Service Management (IEEE TNSM) call for papers’ Special Issue on Efficient Management of SDN and NFV-based Systems:
  • Sign up to attend IEEE NetSoft 2015 dedicated to “Software-Defined Infrastructures for Networks, Clouds and Services.” This is a must-attend event for the latest innovations, developments and tests in the overall SDN/NFV transformation trend, seen also from the business and regulation viewpoints, which is deeply impacting Telecom and IT industries:


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1. Interfaces, Attributes, and Use Cases: A Compass for SDN

Author(s): M. Jarschel, T. Zinner, T. Hossfeld, P. Tran-Gia, and W. Kellerer
This paper appears in: IEEE Communications Magazine
Issue Date: June 2014

The term Software Defined Networking (SDN) is present in most discussions about the future of communications technology, and it means different things to different people. Thus there isno consistent definition at this early stage of its technology development lifecycle. And this fragmented definition of SDN results in fragmented approaches to design,in mixing up the attributes of SDN with those of network virtualization (NFV), and in users not fully understanding the benefits of this technology in terms of cost savings, performance and time-to-market benefits.

The contribution of this article is a thorough definition of SDN and its interfaces as well as a list of its key attributes. Furthermore, the article introduces a SDN compass methodology for mapping of interfaces and attributes to SDN use cases is provided, highlighting the relevance of the interfaces and attributes for each scenario. Among the use cases looked at are:

  • Cloud Orchestration
  • Load Balancing
  • Routing/Forwarding
  • Network Management
  • Application Awareness

It is important to notice that the article outlines tool and a methodology labeled“SDN compass” that could be used to guide potential adopters of SDN on the decision-making process to assesswhether SDN is in fact the right technology for their specific use case.


2. Network Virtualization and Software Defined Networking for Cloud Computing: A Survey

Author(s): R. Jain and S. Paul
This paper appears in: IEEE Communications Magazine
Issue Date: November 2013

Network virtualization is the key to the current and future success of cloud computing. This article covers the key reasons for virtualization, and briefly explains several of the networking technologies that have been developed recently or are being developed in various standards bodies (IEEE, IETF, etc). In particular, the article explains software defined networking(SDN) and why it is the key to network programmability with an illustration called OpenADN which is an application delivery framework in a multi-cloud environment.

The authors look at the existing Internet/Layer 3 architecture to frame the discussion arguing that the key enabler for all virtualizations is the Internet and its supporting computer networking resources.  It also argues the key reasons for virtualization are:

(1) Sharing: When a resource is too big for a single user, it is best to divide it into multiple virtual pieces, as is the case with today’s multi-core processors. Each processor can run multiple virtual machines (VMs), and each machine can be used by a different user. The same applies to high-speed links and large-capacity disks.

(2) Isolation: Multiple users sharing a resource may not trust each other, so it is important to provide isolation among users.

(3) Aggregation: If the resource is too small, it is possible to construct a large virtual resource that behaves like a large resource. This is the case with storage, where a large number of inexpensive unreliable disks can be used to make up large reliable storage.

(4) Dynamics: Often resource requirements change fast due to user mobility, and a way to reallocate the resource quickly is required.

(5) Ease of management: Virtual devices are easier to manage because they are software- based and expose a uniform interface through standard abstractions.

The article surveys how to accomplish them, and gives an example of a new network application, OpenAND, which enables virtualized partitioning and delivery in multi-cloud environment.


3. Are We Ready for SDN? Implementation Challenges for Software-Defined Networks

Author(s): S. Sezer, S. Scott-Hayward, P.K. Chouhan, B. Fraser, D. Lake, J. Finnegan, N. Viljoen, M. Miller, and N. Rao
This paper appears in: IEEE Communications Magazine
Issue Date: July 2013

Cloud services are exploding, and organizations are converging their data centers in order to take advantage of the predictability, continuity, and quality of service delivered by virtualization technologies. In parallel, energy-efficient and high-security networking is of increasing importance to network operators. Software Defined Networking (SDN) has emerged as an efficient network technology capable of supporting the dynamic nature of future network functions and intelligent applications while lowering operating costs through simplified hardware, software, and management. This article addresses the question of how to achieve a successful carrier grade network with SDN. Specific focus is placed on the challenges of network performance, quality, scalability, security, and interoperability with the proposal of potential solution directions.

Today network configuration and installation requires highly skilled personnel adept at configuration of many network elements. Where interactions between network nodes (switches, routers, etc.) are complex, a more systems-based approach encompassing elements of simulation is required. With the current programming interfaces on much of today’s networking equipment, this is difficult to achieve. In addition, operational costs involved in provisioning and managing large multivendor networks covering multiple technologies have been increasing over recent years, while the predominant trend in revenue for operations has been decreasing. Coupled with increasing scarcity of human resources and increasing costs of real estate, this “perfect storm” for service providers is leading to renewed interest in solutions that can unify network management and provisioning across multiple domains. A new network model is required to support this.

In this article, SDN is described with the Open Networking Foundation (ONF) [1] definition: “In the SDN architecture, the control and data planes are decoupled, network intelligence and state are logically centralized, and the underlying network infrastructure is abstracted from the applications.”

The authors’ vision of the future SDN architecture encompasses the complete network platform with separation of the control and data planes, and maintaining carrier grade service. The architecture requirements to meet operational expectations in carrier grade networks are scalability, reliability, quality of service (QoS), and service management. The article contains a good discussion on control-data plane separation challenges. The article also contains a good discussion on how to achieve a programmable switch, and concludes with the outline of a vision for the future of SDN/NFV.

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