Kenji Fujikawa

Development of an Autonomous Distributed Control System for Optical Packet and Circuit Integrated Networks

In this paper, we describe an autonomous distributed control system that we have been developing for an optical packet and circuit integrated network, and we experimentally evaluate its performance. Colored (i.e., multi-wavelength) optical packet-switched links transfer both control signals for circuit switching (e.g., signaling and routing) and best-effort packet data. We successfully transmitted high-definition uncompressed real-time video signals on two lightpaths established by our control system without degradation of video quality, simultaneously with other optical packet data transferred on the same optical fibers. Our developed control system not only achieved autonomous distributed signaling and routing but also has a function that can adjust wavelength resources for optical packet and circuit switching autonomously in each link at each node. Controllers achieved lightpath establishment within approximately 360 ms and dynamic resource adjustment within approximately 454 ms, in the best possible case in our experimental setup.

Control-message exchange of lightpath setup over colored optical packet switching in an optical packet and circuit integrated network

We have proposed the concept of an optical packet and circuit integrated network to provide service diversity, energy efficiency and a simplified control mechanism toward new generation networks. In this integrated network, optical data packets and data on lightpaths are transmitted on common physical resources for efficient resource use. In addition, path signaling for lightpath setup and release thorough optical packet switch block is implemented. We set up a primitive optical packet and circuit integrated network including one switching node and a set of packet/path transceiver. We demonstrate 80 (8λ × 10) Gbit/s colored optical packet switching and 8-lightpaths establishment by transferring optical control packets over the optical packet switching.

Resilient Routing under Hierarchical Automatic Addressing

BGP table size and update rate have increased dramatically in the last decade. The rate of the growth poses great demand on memory size and CPU speed of the router control processor. Hierarchical Automatic Addressing (HAA) reduces BGP table size and update rate by enabling prefix aggregation for multihomed ASes. However, the aggregation blocks routing information of individual ASes, and causes the routing system fails to react to failures. In this paper, we propose a resilient routing protocol referred to as Routing with Detour (RD) to address the problem. RD provides resilient routing under HAA, and it reacts to failures in a timely manner without modifying BGP. Our experiments with realistic AS topology show that RD has slight impact on HAAs performance. More precisely, HAA with RD can reduce BGP table size and update rate by more than 90%.

First development of integrated optical packet and circuit switching node for new-generation networks

We develop an integrated optical packet and circuit switching node in which signaling via optical packet switching is implemented. We demonstrate 80 (8λ × 10) Gbit/s optical packet switching with <1E-4 packet-loss-rate, 8-lightpaths establishment, and dynamic wavelength-resources control.

Inter-AS Locator Allocation of Hierarchical Automatic Number Allocation in a 10,000-AS Network

A Hierarchical Automatic Number Allocation (HANA) protocol, which allocates locators to ASes hierarchically, is one solution for the problem of BGP table increase. We describe hierarchical inter-AS locator allocation by HANA and emulate locator allocation on a huge-scale network consisting of 10,000 ASes, which are extracted from the actual Internet topology. We prove that locator allocation was accomplished only within 13 seconds and traffic yielded by the HANA control messages is only 1.4 Kbps for each session in average. This shows that the HANA protocol allocates locators on a 10,000-scale hierarchical network.

Compact location encodings for scalable Internet routing

The Internet is facing the double-challenge of accelerating growth of routing table size and ever higher reliability requirements. Considerable progress has been made toward the scalability and reliability of the Internet. However, most of the proposals are only partial solutions that address some of the challenges. In this paper, we present a new addressing encoding scheme and a corresponding forwarding mechanism for Internet routing to solve the aforementioned problems. Underlying our design is a succinct data structure that allows us to compactly embed a set of addresses into packet headers. At the same time, the structure allows the data plane to efficiently extract multiple address information for the same destination without decompression. We provide time and space complexity analysis, and present experimental results evaluating the performance of our encoding method. It shows that the proposed encoding method can achieve a good compression factor without degrading packet-forwarding performance.

Experimental performance evaluation of control mechanisms for integrated optical packet- and circuit-switched networks

We are developing an integrated optical packet- and circuit-switched network. In this paper, we feature our own control system of the network and experimentally evaluate its performances. In our experimental setup, both best-effort data and control signals are transferred on colored (i.e. multi-wavelength) optical packet-switched links. We successfully transmit high-definition uncompressed real-time video signals on two lightpaths established by our control system without degradation of video quality, while other packet data are transferred in the same optical fibers. The developed system also has a function of adaptive resource change of packet switching and circuit switching. Time distances for resource change and lightpath setup are negligible, and therefore users do not feel stress for path establishment as the following results prove. Controller PCs can achieve lightpath establishment and automatic resource-allocation within approximately 500ms and 830ms, respectively, at the best possible case in our experimental setup.

ID-Based Communication Framework in Future Networks

The current Internet has followed a location-based communication paradigm, where IP addresses play a significant role not only in locating hosts or in the routing system, but also in the identification of hosts and services. The location-based, host-centric Internet architecture is not efficient and scalable for newly emerged mobile communications in heterogeneous networks and devices. Therefore, research and development of future networks has been shifting to the identifier (ID)-based communication paradigm where IDs, not only the locators, of communication objects, such as devices, users, contents, or services, play significant roles in networking. These IDs are used for the purpose of identification, authentication, and discovery of the communication objects, as well as delivery of services. In this paper, we first present a generalized ID-based communication framework and then show how the recently proposed ID/locator split-based networking and information-centric networking architectures fit into the framework. We then summarize key capabilities and technical challenges brought about by these new proposals, and also present some approaches to possible solutions.

Towards reliable and lightweight source switching for datacenter networks

A low-latency and reliable message switching network is critical for constructing high-speed datacenter networks. In this paper, we present the design, implementation, and evaluation of a novel Location basEd Source Switching (LESS) for datacenter networks. LESS enables lightweight source switching through a location-based addressing scheme. Each switch and host can independently derive a source route to reach a destination without requiring the full knowledge of the network topology. We demonstrate that using location-based source routes as forwarding labels allows LESS to eliminate the need for routing tables and integrate with minimum required functionality for packet forwarding. Moreover, we propose a fast rerouting solution to address the issue of fault tolerance in source routing. Each switch can locally derive an alternative source route during a failure. The paper evaluates the performance of LESS. Our evaluation results suggest that LESS improves the performance of datacenter networks in terms of latency, throughput, and reliability.

Design and implementation of variable-length locator allocation protocol for scalable Internet addressing

Hierarchical address allocation and hierarchical routing design has long been suggested to reduce the forwarding information base (FIB) size in the Internet core. However, the hierarchical design is not put into practice. We implemented the hierarchical and automatic number allocation (HANA) protocol for allocation of IPv4 and IPv6 address spaces to autonomous systems (ASes) and the FIB size reduction. The HANA protocol allocates multiple address spaces to an AS from the upper ASes. Multihoming using multiple addresses provides an AS with multiple paths. That is, detour paths are inevitably prepared in advance, even when a network failure does not occur. In this paper, we provide the highest flexibility to HANA-based networking, namely, supporting variable-length addressing scheme. The variable-length addressing schemes suppress renumbering caused by the address space extension that occurs in the fixed-bit-length addressing schemes. In addition, we propose a new function of exchanging allocated numbers, and implement it in the current HANA system. The flexible HANA system provides locator allocation with low renumbering costs and realizes scalable addressing in future internetworking.