Towards Software-Defined Delay Tolerant Networks

Hauser F., Häberle M., Merling D., Lindner S., Gurevich V., Zeiger F., Frank R., Menth M.

Programmable data planes allow users to define their own data plane algorithms for network devices including appropriate data plane application programming interfaces (APIs) which may be leveraged by user-defined software-defined networking (SDN) control. This offers great flexibility for network customization, be it for specialized, commercial appliances, e.g., in 5G or data center networks, or for rapid prototyping in industrial and academic research. Programming protocol-independent packet processors (P4) has emerged as the currently most widespread abstraction, programming language, and concept for data plane programming. It is developed and standardized by an open community, and it is supported by various software and hardware platforms. In the first part of this paper we give a tutorial of data plane programming models, the P4 programming language, architectures, compilers, targets, and data plane APIs. We also consider research efforts to advance P4 technology. In the second part, we categorize a large body of literature of P4-based applied research into different research domains, summarize the contributions of these papers, and extract prototypes, target platforms, and source code availability. For each research domain, we analyze how the reviewed works benefit from P4's core features. Finally, we discuss potential next steps based on our findings.

Hylton A., Cleveland J., Dudukovich R., Iannicca D., Kortas N., LaFuente B., Nowakowski J., Raible D., Short R., Tomko B., Wroblewski A.

Burleigh S., Fall K., Birrane E.

Sipos B., Demmer M., Ott J., Perreault S.

Musumeci F., Fidanci A.C., Paolucci F., Cugini F., Tornatore M.

Distributed Denial of Service (DDoS) attacks represent a major concern in modern Software Defined Networking (SDN), as SDN controllers are sensitive points of failures in the whole SDN architecture. Recently, research on DDoS attacks detection in SDN has focused on investigation of how to leverage data plane programmability, enabled by P4 language, to detect attacks directly in network switches, with marginal involvement of SDN controllers. In order to effectively address cybersecurity management in SDN architectures, we investigate the potential of Artificial Intelligence and Machine Learning (ML) algorithms to perform automated DDoS Attacks Detection (DAD), specifically focusing on Transmission Control Protocol SYN flood attacks. We compare two different DAD architectures, called Standalone and Correlated DAD, where traffic features collection and attack detection are performed locally at network switches or in a single entity (e.g., in SDN controller), respectively. We combine the capability of ML and P4-enabled data planes to implement real-time DAD. Illustrative numerical results show that, for all tested ML algorithms, accuracy, precision, recall and F1-score are above 98% in most cases, and classification time is in the order of few hundreds of $$\upmu \text {s}$$ in the worst case. Considering real-time DAD implementation, significant latency reduction is obtained when features are extracted at the data plane by using P4 language.

Kim J., Kim H., Rexford J.

Associating network traffic with human-readable domain names, instead of low-level identifiers like IP addresses, is helpful for measuring traffic by domain name, rate-limiting packets by domain, and identifying IoT devices. However, existing monitoring techniques require examining traffic at an external compute node, introducing overhead and privacy risks. In this paper, we introduce Meta4, a framework for monitoring traffic by domain name in the data plane by extracting the client IP, server IP, and domain name from DNS response messages and associating the domain name with data traffic from the subsequent client-server session. A data-plane implementation has the benefits of running efficiently at line-rate, enabling the switch to take direct action on the packets (e.g., to rate-limit, block, or mark traffic based on the associated domain), and protecting the privacy of user information. We implemented Meta4 on an Intel Tofino switch and evaluated our prototype against packet traces from an operational network.

Fraire J.A., De Jonckère O., Burleigh S.C.

A Space Internet is possible, as long as the delay and disruption challenges imposed by the space environment are properly tackled. Because these conditions are not well addressed by terrestrial Internet, more capable Delay-Tolerant Networking (DTN) protocols and algorithms are being developed. In particular, the principles and techniques for routing among ground elements and spacecraft in near-Earth orbit and deep-space are enacted in the Contact Graph Routing (CGR) framework. CGR blends a set of non-trivial algorithm adaptations, space operations concepts, time-dynamic scheduling, and specific graph models. The complexity of that framework suggests a need for a focused discussion to facilitate its direct and correct apprehension. To this end, we present an in-depth tutorial that collects and organizes first-hand experience on researching, developing, implementing, and standardizing CGR. Content is laid out in a structure that considers the planning, route search and management, and forwarding phases bridging ground and space domains. We rely on intuitive graphical examples, supporting code material, and references to flight-grade CGR implementations details where pertinent. We hope this tutorial will serve as a valuable resource for engineers and that researchers can also apply the insights presented here to topics in DTN research.

Bormann C., Hoffman P.

Isong B., Molose R.R., Abu-Mahfouz A.M., Dladlu N.

Software-Defined Networking (SDN) is a network paradigm introduced to overcome the inherent challenges of traditional networks. Its architecture is either deployed with a single controller or multiple controllers. While the first is not suitable for large-scale networks, the latter is confronted with a controller placement problem (CPP) in a large-scale network environment. CPP involves the challenge of deploying the optimal number of controllers within a network while meeting certain performance requirements considered conflicting in nature such as reliability, load balancing, latency, energy efficiency, and computation time. A single optimal or random placement may not be feasible in CPP and careful planning is of the essence to find an appropriate trade-off among the metrics. To achieve this, several CPP approaches have been proposed, developed, and deployed over the years, each having its unique objectives, strengths, and weaknesses. Therefore, this paper performed a comprehensive review of some of the existing approaches to identify the unique solutions offered, comprehend the different strategies and the challenges that exist as well as provide researchers with future directions aimed at improving the optimum location and allocation of controllers, in particular, for SDN application in wireless sensor network (WSN). The findings revealed several existing solutions and algorithms as well as several challenges such as the need for an efficient algorithm, attack-aware, cost-aware, and energy-aware CPP schemes while achieving a good quality of service.

Hylton A., Raible D., Clark G., Dudukovich R., Tomko B., Burke L.

Tao P., Ying C., Sun Z., Tan S., Wang P., Sun Z.

Software Defined Network (SDN) separates control plane from data plane, and uses multiple controllers to resolve the extensibility and security of SDN. However, most research concentrates on the control layer architecture, ignoring the controllers placement problem. In this paper, we first define the total flow request cost that considers switch weights, switch-to-controller routing costs, and inter-controller routing costs. Next, we propose controller-based load balance factor, with a known number of controllers, the position of the specific controllers is derived by minimizing the linear function of the load balance factor and the total flow request cost. Finally, through simulation, the controller layout scheme reduces the flow request cost of the SDN and achieves load balancing among the controllers.

Killi B.P., Reddy E.A., Rao S.V.

Software Defined Networking decouples the control plane from the data plane and shifts the control plane to an external entity known as the controller. In large networks, the control plane is distributed among multiple controllers to satisfy fault tolerant and response time requirements. The network is divided into multiple domains, and one or more controllers are deployed in each of these domains. The naive approach for partitioning the network using the k-means algorithm with random initialization results in solutions that are far from optimal. In this paper, we propose a network partition based controller placement strategy by leveraging k-means algorithm with cooperative game theory initialization. The partitioning of the network into subnetworks is modeled as a cooperative game with the set of all switches as the players of the game. The switches try to form coalitions with other switches to maximize their value. It is referred as cooperative k-means for brevity. We also propose two variants of cooperative k-means strategy that tries to produce partitions that are balanced in size. The performance of our proposed strategies are evaluated on networks from Internet 2 OS3E and Internet Topology Zoo. Results demonstrate that our cooperative k-means strategy generates solutions that are close to optimal in terms of the worst case switch to controller latency and outperforms the standard k-means algorithm. Evaluations also demonstrate that the first variant of cooperative k-means produce balanced partitions when the number of partitions is less while the second variant of cooperative k-means always produces balanced partitions.

Zacarias I., Gaspary L.P., Kohl A., Fernandes R.Q., Stocchero J.M., de Freitas E.P.

Network-centric warfare is a no-way-back trend in modern military operations. The application of this concept ranges from upper-level decision making echelons to troop guidance on the battlefield, and many studies have been carried out in this area. However, most of these are concerned with either the higher-level strategic networks, that is, the networks linking the higher echelons with abundant resources, satellite communications, or even a whole network infrastructure, or high-end TEN, representing resource-rich troops in the field, with military aircraft, battleships, or ground vehicles equipped with powerful wireless communication devices and (almost) unrestricted energy resources for communication. However, these studies fail to take into account the "last-mile TEN," which comprises resource constrained communication devices carried by troopers, equipping sensor nodes deployed in the field or small unmanned aerial vehicles. In an attempt to fill this gap in the studies on battlefield networking, this article seeks to combine software-defined and delay-tolerant approaches to support the diverse range of strict requirements for applications in the last-mile TEN.

Hylton A., Raible D.E.

Burleigh S., Caini C., Messina J.J., Rodolfi M.

Routing in Delay-/Disruption-Tolerant Networking (DTN) has long been recognized as a challenging research topic. The difficulty lies in the fact that link intermittency and network partitioning, possibly coupled with long delays, prevent the use of Internet solutions based on an up-to-date comprehensive knowledge of network topology, as communicated by routing protocols. In the literature on DTN routing, there is a dichotomy between solutions designed for deterministic (e.g., space flight) networks, such as Contact Graph Routing (CGR), and the wide variety of protocols designed for opportunistic terrestrial networks. After a discussion of the origin and motivations of this duality, the paper presents an opportunistic extension of CGR (OCGR). The aim is to try to resolve the DTN routing dichotomy by providing a unified approach suitable for all DTN environments.

Salam M.A., Saif A.F., Katroju P.H., Kassouf-Short R.

Elewaily D.I., Ali H.A., Saleh A.I., Abdelsalam M.M.

Communication with deep-space elements poses significant challenges due to vast distances, orbital motions, and harsh environmental conditions that restrict point-to-point or end-to-end communication. Disruption/Delay-Tolerant Networking (DTNs) is a special kind of computer network architecture, that overcomes the shortcomings of the TCP/IP suite in meeting deep-space networking requirements with intermittent end-to-end connectivity. In DTN, data transmission follows a store-carry-forward approach, where bundles (data) are transferred as custody between relay nodes. This necessitates more complex routing strategies involving additional route computations and network resource consumption but provides greater flexibility for unstable connectivity. This study is an updated literature review in the context of DTN-based deep-space communication. It covers the recent studies that address the architecture of current and future deep-space communication systems, the environmental challenges of deep-space communication, various implementations and demonstrations of DTN's architecture, and the validation of its related routing strategies over the Deep Space Relay network. Additionally, this review explores the integration of machine learning techniques into DTN routing strategies, along with ongoing research directions and open issues in DTN-based DSN. Examining the state-of-the-art literature reveals that developing an intelligent unified n-copy-based forwarding routing scheme holds promise for effectively integrating into deep space communications and achieving optimal networking among the diverse segments of the future unified Interplanetary Internet.

Casey A., Dickey E., Hwang J., Kothari S., Pandey R., Xie W.

Kirkpatrick Y., Dudukovich R., Choksi P., Ta D.