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Feature Articles: Flexible Networking Technologies for Future Networks

Flexible Networking Technologies for Future Networks

Atsushi Hiramatsu, and Ryutaro Kawamura


In recent years, many researchers around the world have been tackling the Future Network, which should supplant the current Next Generation Network (NGN) and the Internet. This article issue describes some examples of research activities on flexible networking in NTT's laboratories; these examples have been selected because they involve important issues with future networks. Flexible networking aims to meet the changes in users' demands, permit easy development of new services, and reduce the capital and operating expenditure costs of existing services.

NTT Network Service Systems Laboratories
Musashino-shi, 180-8585 Japan

1. Introduction

In the last decade, the continuous stream of innovations in networking technologies, such as optical, wireless, the Internet, and the Next Generation Network (NGN), has had a huge impact on us and has significantly enhanced social value in combination with information-processing technologies. As a result, the purposes for which networks are being used have become diversified, and networks have become one of the key social infrastructures.

Based on the evolution of networking and information technologies, many studies on the design of the next-generation network, which they call the Future Network, New Generation Network, or Future Internet, have started. This includes the Network of the Future and Internet of Things (IoT) projects in FP7/EU, FIA (Future Internet Architecture) projects funded by the National Science Foundation (NSF) in the USA, and next-generation network research centered on the NWGN (New Generation Network Promotion) Forum Japan.

2. Key changes in network environments

When we attempt to create a new network concept, one of the important viewpoints must be the changes in the environment-hosting networks. This year is the 50th anniversary of the birth of the Internet. Over that period, the situation surrounding networks has dramatically changed. The main changes are listed in Table 1.

Table 1. Key changes in networking environment.

For example, the main purpose of network users has changed from peer-to-peer connection between two sites to data access to obtain information. The diversity of appliances, such as smartphones and tablets, is increasing rapidly, so the IoT and M2M (machine-to-machine) world will emerge in the near future. From the viewpoint of network traffic, data traffic from/to mobile appliances is increasing very quickly. Moreover, the energy consumed by information and communications technology (ICT) equipment is becoming a major problem. This problem is especially important for NTT because the massive earthquake in 2011 triggered serious energy shortages.

3. Four key flexibilities

Since networks are a social infrastructure, stability has been one of the most important requirements for them. However, to this we must add the ability to respond to the abovementioned changes. We think that flexibility is another key goal when developing future networks. Flexibility is enabled by virtualizing the networking and computing resources, such as bandwidth, routing functions, servers, and storage, and combining them dynamically in order to create new services, balance loads, recover from failures, and so on. Our proposed flexible networking architecture has four layers providing four types of flexibility (Fig. 1). These layers are outlined below and described in more detail in the other Feature Articles in this issue.

Fig. 1. Flexible networking architecture.

The lowest layer holds the flexible optical transport network [1]. This layer virtualizes the resources of the physical network layer and provides them to the higher layers. The network in this layer can dynamically change its topology and bandwidth to suit traffic changes, disasters, and so on.

The second layer is the programmable high-performance network [2], [3]. This is a virtualized network layer that uses the resources provided by the layer below. The virtual nodes include computing resources and combine them with network resources. A virtual node can be altered by software in order to implement new network functions, e.g., protocols.

The third layer is the distributed computing network server infrastructure [4]. This layer provides service functions such as the SIP (session initiation protocol) server in the NGN. The servers are distributed over the virtual networks and collaborate with each other to provide cloud computing. As such, this architecture can dynamically alter the server resources to meet changes such as the adoption of new services and a rapid change in service traffic due to a disaster. Moreover, some data-handling functions such as high-performance packet processing could be performed utilizing this architecture.

These three network layers aim to virtualize and abstract the resources in each layer. Of course, some of them are used together with existing network systems, but the architecture works well when all layers collaborate to combine the various resources available.

The top layer, the ICT resource management platform [2], serves the role of an orchestrator of network resources. This layer also coordinates with computing (information technology (IT)) resources in the cloud. As a result, the Flexible Network accelerates the creation of new network services in combination with IT resources.


[1] Y. Uematsu, A. Masuda, T. Miyamura, and A. Hiramatsu, "Flexible Virtualized Optical Transport Networking Technology," NTT Technical Review, Vol. 10, No. 8, 2012.
[2] K. Yamada, H. Tanaka, N. Takahashi, and R. Kawamura, "Integrated Management of Networks and Information Processing for Future Networks," NTT Technical Review, Vol. 10, No. 8, 2012.
[3] S. Kuwabara, "Monitoring Technology for Programmable Highly Functional Networks," NTT Technical Review, Vol. 10, No. 8, 2012.
[4] T. Fukumoto, M. Iio, and K. Ueda, "Toward Future Network Control Nodes," NTT Technical Review, Vol. 10, No. 8, 2012.


Atsushi Hiramatsu
Executive Manager, Advanced Opto-electronics Laboratory, NTT Photonics Laboratories.
He received the B.E. and M.E. degrees in applied physics from the University of Tokyo in 1984 and 1986, respectively. He joined NTT in 1986. From 1991 to 1992, he was a visiting associate of the Electrical Engineering Department at California Institute of Technology, USA. He received the Paper Award from the Institute of Electronics, Information and Communications Engineers (IEICE) in 1990 and 2000. At the time of the research reported in this article, he was working on broadband optical networks, network virtualization, a software defined transport network, optical packet switching, and a future network architecture as an Executive Manager, Broadband Network Systems Project, NTT Network Service Systems Laboratories. He moved to his current laboratory as of July 1, 2012.
Ryutaro Kawamura
Director, Vice President, Photonic Transport Network Laboratory, NTT Network Innovation Laboratories.
He received the B.S. and M.S. degrees in precision engineering and the Ph.D. degree in electronics and information engineering from Hokkaido University in 1987, 1989, and 1996, respectively. He joined NTT Transport Systems Laboratories in 1989. From 1998 to 1999, he was a visiting researcher in Columbia University, USA. From 2008 to 2010, he was a visiting research expert in the National Institute of Information and Communications Technology. Since 2003, he has been a member of the Board of Directors of the OSGi Alliance, and since 2005, he has been a Vice President for the Asia/Pacific region. He has been engaged in research on network reliability techniques, network control and management, high-speed computer networks, active networks, network middleware, software component technology, and a future network. He is a member of IEEE and IEICE.