Recently, several large-scale software defined networking (SDN) testbeds have been designed and developed. These SDN testbeds have spurred numerous network researchers to run their prototypes and experiments, as well as to set up novel architectures for the future Internet. Based on these efforts, SDN testbeds are actively contributing to future network research, bringing forth the attention of both academia and industry. In addition, researchers envisage these large-scale SDN testbeds to be the future Internet. In this paper, we present a comprehensive survey and research challenges for large-scale SDN testbeds. We first introduce the related work and background knowledge. Then, an overview of SDN testbeds is presented. In addition, five typical implementations of large-scale SDN testbeds around the world are described in detail, including design objectives, key technologies, deployment, and experiments. Moreover, an in-depth comparison of SDN testbeds is given. Finally, challenges and future works of SDN testbeds are discussed.

A Survey on Large-Scale Software Defined Networking (SDN) Testbeds: Approaches and Challenges

Methods, systems, and apparatuses, and combinations and sub-combinations thereof, for down-converting an electromagnetic (EM) signal are described herein. Briefly stated, in embodiments the invention operates by receiving an EM signal and recursively operating on approximate half cycles (½, 1½, 2½, etc.) of the carrier signal. The recursive operations can be performed at a sub-harmonic rate of the carrier signal. The invention accumulates the results of the recursive operations and uses the accumulated results to form a down-converted signal. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal.

Method and system for down-converting an electromagnetic signal, transforms for same, and aperture relationships

An optical packet and circuit integrated network (OPCInet) provides both high-speed, inexpensive services and deterministic-delay, low-data-loss services according to the users’ usage scenarios, from the viewpoint of end users. From the viewpoint of network service providers, this network provides large switching capacity with low energy consumption, high flexibility, and efficient resource utilization with a simple control mechanism. This paper presents the recent progress made in the development of OPCInet and its extension to software-defined networking (SDN). We have developed OPCI nodes, which are capable of layer 3 switching from/to an Ethernet frame to/from an optical packet in the optical packet edge part and a burst-tolerant optical amplifier and an optical buffer with optical fiber delays in 100 Gbps optical packet switching part. The OPCI node achieves a packet error rate less than $10^{-4}$
 and is used as a node in a lab-network that has access to the Internet. A distributed automatic control works in a control plane for the circuit switching part and in a moving boundary control between optical packet resources and circuit resources. Our optical system for packet and circuit switching works with a centralized control mechanism as well as a distributed control mechanism. We have shown a packet-based SDN system that configures mapping between IP addresses and OPCI node identifiers and switching tables according to the requests from multiple service providers via a web interface.

Optical Packet and Circuit Integrated Networks and Software Defined Networking Extension

We developed novel integrated optical packet and circuit switch-node equipment. Compared with our previous equipment, a polarization-independent 4 × 4 semiconductor optical amplifier switch subsystem, gain-controlled optical amplifiers, and one 100 Gbps optical packet transponder and seven 10 Gbps optical path transponders with 10 Gigabit Ethernet (10GbE) client-interfaces were newly installed in the present system. The switch and amplifiers can provide more stable operation without equipment adjustments for the frequent polarization-rotations and dynamic packet-rate changes of optical packets. We constructed an optical packet and circuit integrated ring network testbed consisting of two switch nodes for accelerating network development, and we demonstrated 66 km fiber transmission and switching operation of multiplexed 14-wavelength 10 Gbps optical paths and 100 Gbps optical packets encapsulating 10GbE frames. Error-free (frame error rate < 1×10(-4)) operation was achieved with optical packets of various packet lengths and packet rates, and stable operation of the network testbed was confirmed. In addition, 4K uncompressed video streaming over OPS links was successfully demonstrated.

Development of optical packet and circuit integrated ring network testbed

Methods, systems, and apparatuses for down-converting a modulate carrier signal to a demodulated baseband signal by sampling the energy of the carrier signal are described herein. Briefly stated, such methods systems, and apparatuses operate by receiving a modulated carrier signal and using pulses with apertures to control a switch so as to (a) transfer energy from the modulated carrier signal and accumulate the transferred energy in a capacitor when the switch is closed during the apertures of the pulses and (b) discharge some of the previously accumulated energy from the capacitor into load circuitry at least when the switch is open. The demodulated baseband signal is generated from (i) accumulating energy transferred to the capacitor each time the switch is closed during the apertures of the pulses, and (ii) discharging some of the previously accumulated energy into the load circuitry each time the switch is opened.

Methods and systems for down-converting a signal using a complementary transistor structure

We develop a multi-ring optical packet and circuit integrated network for the first time. Optical buffers are newly installed to a central 3×3 switch-node. 5-node hopping and 244 km transmission of 100 Gbps optical packets with 14 optical paths is achieved at a frame error rate <;1E-4. Successful avoidance of packet collisions by buffers is shown.

A multi-ring optical packet and circuit integrated network with optical buffering

An optical packet switching apparatus includes an optical coupler, an optical switch unit, and an optical switch control unit. The optical switch control unit includes an optical-to-electrical converter, a serial/parallel converter, an arrangement detector, a rearrangement unit, a frame synchronization unit, a route detector, a control signal generator, and an adjustment unit for adjusting the timing with which to output an optical switch control signal to the optical switch unit, based on arrangement information on a frame synchronization pattern fed from the arrangement detector.

Optical packet switching apparatus

An optical transmitter includes a dummy optical source, a polarized wave beam coupler, and an auto gain control (AGC)-system amplifier. The dummy optical source outputs, out of an optical signal in which an optical path signal and an optical packet signal are mixed, a dummy signal having a wavelength identical to that of the optical packet signal. The polarized wave beam coupler multiplexes the dummy signal with the optical signal so that the dummy signal is orthogonal to the optical signal so as to output an output signal. The AGC-system amplifier inputs the output signal, and amplifies the output signal with a predetermined amplification factor corresponding to a power difference between input power and output power of an optical amplifier.

Optical transmitter and optical transmission method

An optical packet switch device includes an optical switch control section and an optical switch section. The optical switch control section includes a synchronization pattern detecting unit which detects a frame synchronization pattern from a parallel data signal and detects a delay bit number showing that the frame synchronization pattern is stored at a position shifted by how many bits from the first bit of the parallel data signal, a header analysis unit which analyzes a header and detects an optical packet length and route information of an optical packet signal, and an output competition determining unit which determines passing/discarding of the optical packet signals competing with each other based on the optical packet length and the route information detected by the header analysis unit and delay bit number information detected by the synchronization pattern detecting unit.

Wataru Kawasaki

Papers

Development of optical packet and circuit integrated ring network testbed

A multi-ring optical packet and circuit integrated network with optical buffering

Optical packet switching apparatus

Optical transmitter and optical transmission method

Optical packet switch device