Steinar Bjornstad

Bio: Steinar Bjornstad is an academic researcher from Norwegian University of Science and Technology. The author has contributed to research in topics: Network packet & Burst switching. The author has an hindex of 11, co-authored 65 publications receiving 428 citations. Previous affiliations of Steinar Bjornstad include University of Oslo & Telenor.

A packet-switched hybrid optical network with service guarantees

Abstract: We show that our proposed optical packet switched (OPS) hybrid network model supports both high throughput efficiency and guaranteed service transport (GST) with no packet loss and constant delay. The network comprises a wavelength routed optical network (WRON) enabling GST, and a statistically multiplexed (SM) network enabling high throughput. In the WRON, packets follow a fixed wavelength path and forwarding is based on the packets wavelength, while in the SM network, packets are switched according to header information. High reliability of GST packet forwarding is possible, because the forwarding does not depend on the operation of the packet switch. A novel node design supporting three Quality of Service (QoS) classes is proposed and described in detail. It facilitates full sharing of the link bandwidth by segregating GST packets and SM packets using polarization time division multiplexing (PTDM). SM packets are differentiated into two specified sub-QoS classes employing a novel buffer reservation technique and asynchronous buffer scheduling algorithm AIP3Q. We present a detailed analysis of the node throughput performance, demonstrating that buffering resource requirements are reduced in the optical packet switch, because processing and buffering of GST packets is avoided. The SM packet QoS differentiation permits a further reduction of buffer resources

Field-trial demonstration of cost efficient sub-wavelength service through integrated packet/circuit hybrid network [invited]

Abstract: Carriers are under constant pressure to meet the ever-increasing bandwidth demand while reducing cost per bit, enhancing network throughput, and offering a large variety of services. Hybrid packet and circuit network technologies are being widely investigated and considered as a solution for offering both the high network throughput of the packet domain and wavelength services, i.e., a low fixed latency and zero packet loss. To enable carriers to serve a higher number of customers requiring wavelength services, optical transport network (OTN)-based sub-wavelength switching is adopted to support finer granularity with similar performance to full wavelength services. However, OTN is not able to perform statistical multiplexing and achieve the throughput efficiency of packet networks. In this work an integrated hybrid optical network field-trial is described to demonstrate the ability to both aggregate and transport sub-wavelength circuits, and offer high throughput efficiency by statistically multiplexing traffic on transport wavelengths. Results show the transport of sub-wavelength services with packet-delay variation limited to only 15 ns and 82.4% wavelength utilization using statistical multiplexing.

Scalability analysis of SDN-controlled optical ring MAN with hybrid traffic

Abstract: The development of software defined networking (SDN) has instigated a growing number of experimental studies which demonstrate the flexibility in network control and management introduced by this technique. Optical networks add new challenges for network designers and operators to successfully dimension and deploy an SDN-based in the optical domain. At present, few performance evaluations and scalability studies that consider the high-bandwidth of the optical domain and the flow characterization from current Internet statistics have been developed. In this paper these parameters are taken as key inputs to study SDN scalability in the optical domain. As a relevant example an optical ring Metropolitan Area Network (MAN) is analyzed with circuit and packet traffic integrated at the wavelength level. The numerical results characterize the limitations in network dimensioning when considering an SDN controller implementation in the presence of different flow mixes. Employing flow aggregation and/or parallel distributed controllers is outlined as potential solution to achieve SDN network scalability.

An optical packet switch design with shared electronic buffering and low bit rate add/drop inputs

Abstract: An optical packet switch design using optical switching and shared electronic buffering is described and analyzed. The electronic buffering and add/drop unit allows random memory access, variable packet length, and aggregation/segregation of low bit rate streams. The design is scalable to a large number of wavelengths, and employs contention resolution by using the wavelength dimension combined with electronic buffering. The number of buffer inputs, i.e. the number of optoelectronic conversions, is minimized. The packet loss and delay performance when using fixed packet length and electronic buffering are investigated by simulation. If the link utilization is moderate, the buffering requirements becomes minimal. If number of wavelengths in the link is increased, the number of buffer inputs can be reduced. With a sufficiently high number of wavelengths, the buffer requirements is minimal, even when the link utilization is high.

Quality of service in optical packet switched DWDM transport networks

Abstract: For support of multimedia applications in Internet, at least four service classes are normally outlined. We expect optical packet switching to be of special interest in terabit capacity networks with a high number of wavelengths. Our analysis shows that when the wavelength dimension is used for contention resolution, and number of wavelengths is 32 or higher, node-delay is negligible. However buffering in optical packet switches is a scarce resource which use should be minimized. Based on the requirement of the future network, and on our packet switch performance analysis, we suggest reducing the number of service classes to two: A normal class (NCT) with medium low packet loss and a low need for buffering, and a high class (HCT) with a minimum of packet loss. Performance of a buffer reservation scheme is analyzed by simulation. Assuming the network of today with 10 % HCT traffic, assigning four buffer inputs to the HCT traffic, a difference in optical packet loss ratio of three orders of magnitude can be obtained. The same difference in optical packet loss ratio can be obtained if 50 % HCT traffic is assumed (network of tomorrow), by assigning a higher number of buffer inputs.

Optical burst switching (OBS) - a new paradigm for an optical Internet

Abstract: To support bursty traffic on the Internet (and especially WWW) efficiently, optical burst switching (OBS) is proposed as a way to streamline both protocols and hardware in building the future gener...

Software Defined Optical Networks (SDONs): A Comprehensive Survey

Abstract: The emerging software defined networking (SDN) paradigm separates the data plane from the control plane and centralizes network control in an SDN controller. Applications interact with controllers to implement network services, such as network transport with quality of service. SDN facilitates the virtualization of network functions so that multiple virtual networks can operate over a given installed physical network infrastructure. Due to the specific characteristics of optical (photonic) communication components and the high optical transmission capacities, SDN-based optical networking poses particular challenges, but holds also great potential. In this article, we comprehensively survey studies that examine the SDN paradigm in optical networks; in brief, we survey the area of software defined optical networks (SDONs). We mainly organize the SDON studies into studies focused on the infrastructure layer, the control layer, and the application layer. Moreover, we cover SDON studies focused on network virtualization, as well as SDON studies focused on the orchestration of multilayer and multidomain networking. Based on the survey, we identify open challenges for SDONs and outline future directions.

Software-defined networking (SDN): a survey

Abstract: With the advent of cloud computing, many new networking concepts have been introduced to simplify network management and bring innovation through network programmability. The emergence of the software-defined networking (SDN) paradigm is one of these adopted concepts in the cloud model so as to eliminate the network infrastructure maintenance processes and guarantee easy management. In this fashion, SDN offers real-time performance and responds to high availability requirements. However, this new emerging paradigm has been facing many technological hurdles; some of them are inherent, while others are inherited from existing adopted technologies. In this paper, our purpose is to shed light on SDN related issues and give insight into the challenges facing the future of this revolutionary network model, from both protocol and architecture perspectives. Additionally, we aim to present different existing solutions and mitigation techniques that address SDN scalability, elasticity, dependability, reliability, high availability, resiliency, security, and performance concerns. Copyright © 2017 John Wiley & Sons, Ltd.

Analysis of Power Consumption in Future High-Capacity Network Nodes

Abstract: Power consumption and the footprint of future network elements are expected to become the main limiting factors for scaling the current architectures and approaches to capacities of hundreds of terabits or even petabits per second. Since the underlying demand for network capacity can be satisfied only by contemporaneously increasing transmission bit rate, processing speed, and switching capacity, it unavoidably will lead to increased power consumption of network nodes. On the one hand, using optical switching fabrics could relax the limitations to some extent, but large optical buffers occupy larger areas and dissipate more power than electronic ones. On the other hand, electronic technology has made fast progress during the past decade regarding reduced feature size and decreased power consumption. It is expected that this trend will continue in the future. This paper addresses power consumption issues in future high-capacity switching and routing elements and examines different architectures based on both pure packet-switched and pure circuit-switched designs by assuming either all-electronic or all-optical implementation, which can be seen as upper and lower bounds regarding power consumption. The total power consumption of a realistic and appropriate technology for future high-performance core network nodes would probably lie somewhere between those two extreme cases. Our results show that implementation in optics is generally more power efficient; especially circuit-switched architectures have a low power consumption. When taking into account possible future developments of Si CMOS technology, even very large electronic packet routers having capacities of more than hundreds of terabits per second seem to be feasible. Because circuit switching is more power efficient and easier to implement in optics than pure packet switching, the scalability limitation due to increased power consumption could be considerably relaxed when a kind of dynamic optical circuit switching is used within the core network together with an efficient flow aggregation at edge nodes.

Obfuscating Network Traffic from Previously Collected Network Traffic

Abstract: An obfuscated network traffic server is operative to generate obfuscated network traffic. The obfuscated network traffic server maintains the relationship between extracted application content and extracted network header content such that the obfuscated network traffic is indistinguishable from the monitored network traffic. The obfuscated network traffic server may include a network monitor operative to monitor network traffic and to extract application content and network header content from the monitored network traffic. The obfuscated network traffic server may also include a data masking processor operative to mask a portion of the separated application content and/or the separated network header content. The obfuscated network traffic server may further include a masking attribute selector operative to specify the attributes of the application content and/or the network header content that is to be masked.