The emergence of new services in the cloud computing era has made smooth service migration an important issue in access networks. However, different types of equipment are typically used for the different services due to differences in service requirements. This leads to an increase in not only capital expenditures but also operational expenditures. Here we propose using a service adaptive approach as a solution to this problem. We analyze the requirements of a future access network in terms of service, network, and node. We discuss available access network technologies including the passive optical network, single star network. Finally, we present a future service adaptive access/aggregation network and its architecture along with a programmable optical line terminal and optical network unit, discuss its benefit, and describe example services that it would support.

Generalized Multi-protocol Label Switching (GMPLS) technologies are expected a key technology that creates high-performance Internet backbone networks. There were many GMPLS interoperability trials. However, most of them reported the successful results only. How to set up a trial network and how to test it was generally not discussed. In this paper, as a kind of tutorial, detailed GMPLS field trials in the National Institute of Information and Communications Technology (NICT) Kei-han-na Info-Communication Open Laboratory, Interoperability Working Group (WG) are reported. The interoperability WG is aiming at the leading edge GMPLS protocol based Inter-Carrier Interface that utilizes wide-bandwidth, cost-effective photonic technology to implement IP-centric managed networks. The interoperability WG is a consortium for researching the GMPLS protocol and advancing a de facto standard in this area. Its experimental results, new ideas, and protocols are submitted to standardization bodies such as the International Telecommunications Union-Telecommunication standardization sector (ITU-T), the Internet Engineering Task Force (IETF), and the Optical Internetworking Forum (OIF). This paper introduces the activities of the interoperability WG; they include a nationwide GMPLS field trial using the JGN II network with multi-vendor, multi-switching-capable equipment and a GMPLS multi routing area trial that used a multi-vendor lambda-switching-capable network.

This paper proposes a scalable active optical access network using high-speed Plumbum Lanthanum Zirconate Titanate (PLZT) optical switch/splitter. The Active Optical Network, called ActiON, using PLZT switching technology has been presented to increase the number of subscribers and the maximum transmission distance, compared to the Passive Optical Network (PON). ActiON supports the multicast slot allocation realized by running the PLZT switch elements in the splitter mode, which forces the switch to behave as an optical splitter. However, the previous ActiON creates a tradeoff between the network scalability and the power loss experienced by the optical signal to each user. It does not use the optical power efficiently because the optical power is simply divided into 0.5 to 0.5 without considering transmission distance from OLT to each ONU. The proposed network adopts PLZT switch elements in the variable splitter mode, which controls the split ratio of the optical power considering the transmission distance from OLT to each ONU, in addition to PLZT switch elements in existing two modes, the switching mode and the splitter mode. The proposed network introduces the flexible multicast slot allocation according to the transmission distance from OLT to each user and the number of required users using three modes, while keeping the advantages of ActiON, which are to support scalable and secure access services. Numerical results show that the proposed network dramatically reduces the required number of slots and supports high bandwidth efficiency services and extends the coverage of access network, compared to the previous ActiON, and the required computation time for selecting multicast users is less than 30 msec, which is acceptable for on-demand broadcast services.

We report the first successful experiment on Point-to-Multipoint (P2MP) VLAN path establishment on the overlay-model-based GMPLS-controlled wide area Ethernet. To support the overlay model, P2MP VLAN path signaling with egress output port indication is proposed and implemented. It is confirmed that our extended RSVP-TE software can correctly establish P2MP VLAN paths in the overlay-model network.

The energy consumption of network virtualization environments (NVEs) has become a critical issue. In this paper, we focus on reducing the data switching energy consumption of NVE. We first analyze the data switching energy of NVE. Then, we propose a dynamic energy efficient virtual link resource reallocation (eEVLRR) approach for NVE. eEVLRR dynamically reallocates the energy efficient substrate resources (s-resources) for virtual links with dynamic changes of embeddable s-resources to save the data switching energy. In order to avoid traffic interruptions while reallocating, we design a cross layer application-session-based forwarding model for eEVLRR that can identify and forward each data transmission flow along the initial specified substrate data transport path until end without traffic interruptions. The results of performance evaluations show that eEVLRR not only guarantees the allocated s-resources of virtual links are continuously energy efficient to save data switching energy but also has positive impacts on virtual network acceptance rate, revenues and s-resources utilization.

In a grid computing environment, the network characteristics such as bandwidth and latency affect the task performance. The demands for bandwidth of wide-area networks become large and it reaches more than 100 Gbps. In this article, we focus on parallel routes transmission, such as link aggregation, to realize large bandwidth network. The performance of grid computing with parallel routes transmission is evaluated on the emulated wide-area network.

This paper describes the recently developed 816 delivery and coupling switch (DC-switch) boards for constructing a 320-Gb/s throughput (2. 5 Gb/s 8 multiplexed wavelengths 16 incoming/outgoing link pairs) optical path cross-connect (OPXC) system based on wavelength path (WP) and virtual wavelength path (VWP) schemes. The DC-switch-based OPXC system, compared with conventional space division switch (SD-switch)-based OPXC system architecture, is shown to be superior in terms of; i) high link modularity, ii) upgradability from WP network to VWP network, iii) better transmission characteristics, and iv) lower total switching power consumption. Therefore, the DC-switch-based OPXC system can realize cost-effective optical path networks. The developed DC-switches exploit the silica-based planar lightwave circuit (PLC) technologies, and DC-switch board size is 300330 mm2 (one switch). The worst values of the insertion loss of the board, ON/OFF ratio, and polarization dependent loss are 14. 5 dB, 34 dB and 0. 5 dB, respectively. Moreover, even though switching is realized by thermo-optic effects, the optical output level varies by only 0. 7 dB and 0. 8 dB for ON- and OFF-state signals, respectively, when the environmental temperature is varied from 5 to 65 .

Software defined networking (SDN) and OpenFlow, which enables the abstraction of vendor/technology-specific attributes, improve the control and management flexibility of optical transport networks. In this paper, we present an interoperability demonstration of SDN/OpenFlow-based optical path control for multi-domain/multi-technology optical transport networks. We also summarize the abstraction approaches proposed for multi-technology network integration at SDN controllers.

A wavelength division multiplexing (WDM) optical path-based Internet protocol (IP) backbone network is proposed as a cost-effective way of realizing robust IP-over-photonic systems. The WDM optical path is based on WDM transmission and wavelength routing. Between end-to-end IP backbone routers, the WDM optical path, a fat and robust optical pipe, is defined across photonic transport systems (PTS's). Tera-bit class PTS's will be required for the future IP backbone network and this level of performance is achievable. Optical layer routing is done at intermediate nodes, so the electrical packet-by-packet routing required by existing systems is eliminated. An optical signal format that permits cost-effective IP packet transmission is presented. WDM optical paths directly accommodate the IP packets via layer-2 frames. The cost-effectiveness of the proposed system, especially for heavy traffic, is demonstrated from the viewpoint of the overall network traffic transport capability and network node cost. The proposed system is as robust as existing systems; e. g. fault/degradation localization mechanism and optical layer network protection one are implemented. Thus the proposed IP-over-photonic system will create cost-effective and robust IP backbone networks.

Creating a bandwidth abundant B-ISDN requires the further development of path technologies. Optical path cross-connect nodes (OXCs) will be required that offer very high levels of expandability. The present limited traffic demands must be efficiently supported while permitting easy step-wise expansion in capacity. This paper proposes two OXC architectures that offer high modularity with regard to incoming/outgoing links or the number of multiplexed wavelengths in each link. This paper briefly reviews, for optical path realization, the wavelength path (WP) and the virtual wavelength path (VWP) techniques. The proposed OXC architectures provide flexibility and minimum investment to encourage introduction but support incremental network growth and investment to match traffic demand. The architectures make it easy to upgrade a WP network to a VWP network, simply by replacing some optical components. It is also shown that the proposed OXC architectures ensure effective optical signal detection after a long-haul optical fiber transmission because they minimizes signal power losses within the OXC. Therefore, the proposed OXC architecture can be applied to global area networks. The proposed OXC architectures will play a key role in realizing the optical path infrastructure for the future bandwidth abundant B-ISDN.

Connection setup on various computer networks is now achieved by GMPLS. This technology is based on the source-routing approach, which requires the source node to store metric information of the entire network prior to computing a route. Thus all metric information must be distributed to all network nodes and kept up-to-date. However, as metric information become more diverse and generalized, it is hard to update all information due to the huge update overhead. Emerging network services and applications require the network to support diverse metrics for achieving various communication qualities. Increasing the number of metrics supported by the network causes excessive processing of metric update messages. To reduce the number of metric update messages, another scheme is required. This paper proposes a connection setup scheme that uses flooding-based signaling rather than the distribution of metric information. The proposed scheme requires only flooding of signaling messages with requested metric information, no routing protocol is required. Evaluations confirm that the proposed scheme achieves connection establishment without excessive overhead. Our analysis shows that the proposed scheme greatly reduces the number of control messages compared to the conventional scheme, while their blocking probabilities are comparable.

Machine-to-Machine (M2M) communication is expected to grow in networks of the future, where massive numbers of low cost, low function M2M terminals communicate in many-to-many manner in an extremely mobile and dynamic environment. We propose a network architecture called Data-centric Network (DCN) where communication is done using a data identifier (ID) and the dynamic data registered by mobile terminals can be retrieved by specifying the data ID. DCN mitigates the problems of prior arts, which are large size of routing table and transaction load of name resolution service. DCN introduces concept of route attraction and aggregation in which the related routes are attracted to an aggregation point and aggregated to reduce routing table size, and route optimization in which optimized routes are established routes to reduce access transaction load to the aggregation points. These allow the proposed architecture to deal with ever increasing number of data and terminals with frequent mobility and changes in data.

A domain-specific networking platform based on optically interconnected reconfigurable communication processors is proposed. Some application examples of the reconfigurable communication processor and networking experiment results are presented.

The objectives of this survey are to provide an in-depth coverage of a few selected research papers that have made significant contributions to the development of Network Function Virtualization (NFV), and to provide readers insights into the key advantages and disadvantages of NFV and Software Defined Networks (SDN) when compared to traditional networks. The research papers covered are classified into four categories: NFV Infrastructure (NFVI), Network Functions (NFs), Management And Network Orchestration (MANO), and service chaining. The NFVI papers describe “framework” software that implement common functions, such as dynamic scaling and load balancing, required by NF developers. Papers on NFs are classified as offering solutions for software switches or middleboxes. MANO papers covered in this survey are primarily on resource allocation (virtual network embedding), which is an orchestrator function. Finally, service chaining papers that offer examples and extensions are reviewed. Our conclusions are that with the current level of investment in NFV from cloud and Internet service providers, the promised cost savings are likely to be realized, though many challenges remain.

A flexible orthogonal frequency-division multiplexing optical network enables the bandwidth to be flexibly changed by changing the number of sub-carriers. We assume that users request to dynamically change the number of sub-carriers. Dynamic bandwidth changes allow the network resources to be used more efficiently but each change takes a significant amount of time to complete. Service centric resource allocation must be considered in terms of the waiting time needed to change the number of sub-carriers. If the user demands drastically increase such as just after a disaster, the waiting time due to a chain-change of bandwidth becomes excessive because disaster priority telephone services are time-critical. This paper proposes a Grouped-elastic spectrum allocation scheme to satisfy the tolerable waiting time of the service in an optical fiber link. Spectra are grouped to restrict a waiting time in the proposed scheme. In addition, the proposed scheme determines a bandwidth margin between neighbor spectra to spectra to prevent frequent reallocation by estimating real traffic behavior in each group. Numerical results show that the bandwidth requirements can be minimized while satisfying the waiting time constraints. Additionally measurement granularity and channel alignment are discussed.

This paper presents past and recent trends of optical networks and addresses the future directions. First, we describe path networks with the historical backgrounds and trends. path networks have advanced by using various multiplexing technologies. They include time-division multiplexing (TDM), asynchronous transfer mode (ATM), and wavelength-division multiplexing (WDM). ATM was later succeeded to multi-protocol label switching (MPLS). Second, we present generalized MPLS technologies (GMPLS). In GMPLS, the label concept of MPLS is extended to other labels used in TDM, WDM, and fiber networks. GMPLS enables network operators to serve networks deployed by different technologies with a common protocol suite of GMPLS. Third, we describe multi-layer traffic engineering and a path computation element (PCE). Multi-layer traffic engineering designs and controls networks considering resource usages of more than one layer. This leads to use network resources more efficiently than the single-layer traffic engineering adopted independently for each layer. PCE is defined as a network element that computes paths, which are used for traffic engineering. Then, we address software-defined networks, which put the designed network functions into the programmable data plane by way of the management plane. We describe the evaluation from GMPLS to software defined networking (SDN) and transport SDN. Fifth, we describe the advanced devices and switches for optical networks. Finally, we address advances in networking technologies and future directions on optical networking.

A wavelength division multiplexing (WDM) optical path-based Internet protocol (IP) backbone network is proposed as a cost-effective way of realizing robust IP-over-photonic systems. The WDM optical path is based on WDM transmission and wavelength routing. Between end-to-end IP backbone routers, the WDM optical path, a fat and robust optical pipe, is defined across photonic transport systems (PTS's). Tera-bit class PTS's will be required for the future IP backbone network and this level of performance is achievable. Optical layer routing is done at intermediate nodes, so the electrical packet-by-packet routing required by existing systems is eliminated. An optical signal format that permits cost-effective IP packet transmission is presented. WDM optical paths directly accommodate the IP packets via layer-2 frames. The cost-effectiveness of the proposed system, especially for heavy traffic, is demonstrated from the viewpoint of the overall network traffic transport capability and network node cost. The proposed system is as robust as existing systems; e. g. fault/degradation localization mechanism and optical layer network protection one are implemented. Thus the proposed IP-over-photonic system will create cost-effective and robust IP backbone networks.

Recent technical advances in WDM (Wavelength Division Multiplexing) technologies suggest that their practical application is imminent. By adopting WDM technologies in the transport network, a bandwidth abundant B-ISDN could be realized cost-effectively. This requires the introduction of WDM technologies, especially into the path layer. This paper explores optical path cross-connect (OPXC) nodes that offer very high levels of expandability because existing traffic demands, which are rather limited, must be efficiently supported while permitting easy step-wise expansion in capacity. This paper highlights modularity with regard to incoming/outgoing links. The OPXC architecture that offers the highest modularity is elaborated, and its transmission characteristics, optical loss and switching power consumption are evaluated. This paper also examines OPXC architecture considering the interface needed to connect electrical path cross-connects. The proposed OPXC architectures provide flexibility and minimum investment to encourage the early introduction of B-ISDN and also supports incremental network growth to match traffic demand. The design of OPXC parameters in terms of transmission performance is shown to ensure the applicability of the proposed OPXC architecture to long-haul optical fiber transmission networks. This is made possible with the low optical component losses offered by the OPXC. The proposed OPXC architectures will, therefore, be applied not only to regional networks, but also to global area networks. Thus they will play a key role in realizing the optical path infrastructure for the future bandwidth abundant B-ISDN.

In this paper the current trends in the optical networking including the physical components, technologies and control architectures are discussed. The possible interaction schemes and implementation models of the automatic communication between applications and network as well as between ASON/GMPLS based network domains are proposed. Finally, the related research activities based on simulation results of control plane dimensioning are illustrated and real test bed experiments on OIF worldwide interoperability demonstration and the ongoing European IST project MUPBED are disseminated.