Large-scale packet queueing and scheduling is the basis for today's Quality of Service (QoS) in computer access networks, especially to achieve guaranteed high throughput and low latency. The throughput of a single network function, implementing the QoS functionality for a large number of customers, is in the range of hundreds of gigabits or even more. Therefore, a good performance of the underlying hardware is mandatory. While highly-performant fixed-function ASICs offer sufficient functionality for most data center use cases, as of today, they cannot support all functionality required for access networks, including QoS-aware packet queuing. In this paper, we first analyze mobile and residential Internet access requirements from an Internet service provider perspective, focusing on the QoS-aware packet queueing needs. Considering this analysis, we present a universal and generic FPGA design for high-performance packet queueing and scheduling. Our evaluation results show that FPGAs can be used to implement a deterministic QoS packet queueing system with high performance. This concept can extend today's programmable networking ASICs with the desired functionality as an offloaded “sidecar”.

Large-scale packet queueing and scheduling is the basis for today’s Quality of Service (QoS) in computer access networks, especially to achieve guaranteed high throughput and low latency. While highly performant fixed-function ASICs offer sufficient functionality for most data center use-cases, as of today, they cannot support all functionality required for access networks, e.g., QoS-aware packet queueing.In this poster, we present an FPGA-based architecture for network packet queueing optimized for residential and mobile Internet access networks.

Large-scale telecommunications providers have to continuously challenge and evolve their network infrastructure to efficiently serve growing markets demands. They must increase performance, lower time-to-market, provide new services, and lower the cost of the infrastructure and its operation. Network Functions Virtualization (NFV) on commodity hardware offers an attractive, low-cost platform to establish innovations much faster than with purpose-built hardware products. Unfortunately, implementing NFV on commodity processors does not match the performance requirements of the high-throughput data plane components in large carrier access networks. In this article, we propose a way to offer residential network access with programmable packet processing architectures. Based on the highly flexible P4 programming language, we present a design and open source implementation of a BNG data plane that meets the challenging demands of Broadband Network Gateways in carrier-grade environments. The proposed evaluation results show the desired performance characteristics and our proposed design together with upcoming P4 hardware can offer a giant leap towards highest performance NFV network access.

Bare-metal switches (BMS) are switches sold without an operating system (OS), i.e. including only the switch hardware. For network operators this may not only provide a cost advantage, it also allows them to customize the OS behavior to their own needs. The aim of this demonstration is to show the applicability of BMS in a carrier-grade environment. To this end, a representative use case has been implemented on a BMS, which includes the healing of RTP packet loss by automatically selecting a stream with the least packet loss from redundant uplinks. This use case demonstrates the flexibility of BMS to be adaptable to even such specific needs in a network.

Human activity patterns such as communication and cooperation rely in large parts on smartphone-based interaction. Day-to-day available communication means are taken for granted. But in scenarios where communication infrastructure is broken, such as in the aftermath of a disaster, communication establishment becomes crucial. In those post-disaster conditions ubiquitous mobile devices carried by humans can be used to establish basic ad-hoc communication services in order to aid first responders or to organize volunteers. However, these services rely heavily on the runtime of the utilized mobile devices and therefore network failure and communication capability show a strong dependency on the lifetime of mobile devices. In this paper, the potentials of decentralized resource allocation strategies in mobile networks, with harsh post-disaster conditions, are examined. Considering energy resources to prolong functioning of basic post disaster communication services, different resource allocation strategies are proposed. Through an extensive simulation study we show that (i) the proposed strategies for resource allocation lead to significant improvement of the lifetime of the mobile devices (up to 7.8%) and (ii) the time in which a stable service quality (w.r.t. to the received messages) is provided can be extended by 80% compared to the baseline.

The current ecosystem of network elements, such as switches and appliances, is largely dominated by devices supplied and sold with a bundled operating system, and software dedicated to manage the device's forwarding hardware, however, these platforms are not open-source and cannot be arbitrarily customized, and there is no cost transparency or flexibility in choosing software different to the bundled components.,,,,In this paper, we explore the capabilities of bare-metal switches, which are equipped with commodity switching hardware components, but shipped without an operating system. We evaluate the feasibility of these commonly lower-cost devices to meet the requirements of a customized, carrier-grade network function. Therefore, we have implemented a prototype on generic hardware, re-using as much open-source software as possible. Our Broadband Remote Access Server (BRAS) prototype can lower the cost compared to proprietary network appliances, and, known to have a hardware backplane capacity of 720 Gbps, the merchant-silicon / ASIC approach can highly outperform the state of the art of current x86-based virtualized network functions, while implementing the most important BRAS features.

Network functions virtualization (NFV) environments can provide increased elasticity and flexibility for operators, as network-related services can be scaled and moved as needed. Such operations require a seamless transfer of state to provide a service without interruption or performance degradation. In this paper, we propose and analyze a novel approach for efficient and seamless NFV state transfers. Our approach is based on the concept of statelets, which are compact representations of information in incoming packets that change the state of a virtualized network function. We present and describe slim migration (SliM), a system for efficient NFV state transfers using a statelet interface that we have implemented as an add-on to the data plane development kit, a high-performance packet I/O library. We have evaluated SliM in a testbed and present results that show its benefits in terms of lower delays and lower packet-loss rates. Moreover, our analysis and evaluation results show that SliM offers three times as much shared link capacity to the dataplane as previous approaches, while reducing the duration of a state transfer to one-third of their time.

Instance migration and scale-in/out operations in network functions virtualization (NFV) require state transfer mechanisms, which are known to cause service degradation through increased jitter and packet loss. Techniques such as packet duplication for state synchronization mitigate this problem, however, they incur significant additional costs. In this paper, we provide a novel interface to the VNF to announce “statelets” for incoming packets, which comprise only the information in the packet which is required for a VNF's internal state change. Based on this interface, we design and implement SliM, a statelet-based framework for seamless VNF migration. First evaluation results show that SliM operates seamlessly at very high dataplane utilization of physical links, up to 3 times the utilization level at which existing approaches are failing due to insufficient bandwidth for state synchronization.

Instead of retrieving content from a mobile infrastructure, devices may transmit it between each other, which is referred to as Device-to-Device (D2D) content delivery. This paradigm especially helps the mobile network operator to offload its infrastructure from the delivery of popular content. Private-Share is an application for the Android platform, which enables the user to synchronize content with D2D techniques over Wi-Fi Direct. While being useful for the device owner, it is also a platform for research on several aspects of user behavior and various D2D transmission-or environmental parameters. This paper introduces PrivateShare and discusses first results, which show that most Wi-Fi Direct neighbors are encountered during usual busy times, but also a certain fraction of likely residential devices are encountered overnight.

Device-to-Device (D2D) content delivery is an emerging approach, where end-user devices exchange content with other end-user devices in communication range, instead of retrieving content from an operator's infrastructure. This way, the operator network can be offloaded from congestion caused by the transmission of popular content, and the content consumer's quality of experience may increase. However, D2D content delivery is only effective in situations where a device in proximity has the requested content available, which is more likely to happen with popular content in crowded areas. The availability of content in communication range of a consumer constitutes an upper bound of the success of a D2D content delivery mechanism, which is referred to as the potential of D2D delivery. This paper provides a quantitative answer to the question of this potential, and identifies the most important properties a D2D mechanism must provide. An evaluation model is proposed and developed, which can be applied to real-world mobile user traces to determine the quota of content requests that could be served via D2D content delivery. The model is applied on a dataset of a major European Internet service provider and the evaluation results are discussed. The paper concludes that there is potential to deliver up to 60% of requests for popular content via D2D, if a reliable mechanism to predict a user's content consumption is available.

Mobile ad hoc networks (MANETs) represent a crucial alternative to deploy applications in urban areas. In those networks, it is inevitable that all nodes are aware of the current system state to adapt their behavior according to the varying conditions. However, existing decentralized monitoring solutions for MANETs only locate the required information at a set of nodes, which are in charge of serving the remaining network, while the availability of information depends on the accessibility of those nodes. To avoid these limitations, BlockTree is a novel, fully decentralized monitoring approach for MANETs that leverages each node's resources to capture and distribute the system state to all nodes. Exploiting its hierarchical structure, BlockTree introduces the concept of location-aware monitoring delivering detailed as well as aggregated information. Through robust communication paired with the stateless design, BlockTree provides accurate results in the presence of fast moving nodes or over an error-prone communication medium.