5G mobile communication systems will need to accommodate a variety of use-cases, resulting in a diverse set of requirements. To meet these requirements, 5G systems take advantage of modern virtualization possibilities offered by Network Function Virtualization (NFV), enabling deployment agility and dynamicity of virtualized network functions. With the transformation of telecom towards virtualized environments, advanced observability possibilities gain increasing importance as one of the essential prerequisites, especially for successful DevOps operations. However, deployment agility also puts specific requirements on monitoring solutions in order to adapt automatically and continuously to frequent changes in service deployments. In this short-paper, we establish and discuss essential properties of observability systems for virtual network functions in a 5G context. We take these properties as guiding design principles for our software-defined monitoring framework and outline how to evolve our existing components towards a flexible, scalable, and programmable observability solution for microservice-based NFV with features for increased manageability.

This experience paper describes the process of leveraging the NFV orchestration platform built in the EU FP7 project UNIFY to deploy a dynamic network service exemplified by an elastic router. Elasticity is realized by scaling dataplane resources as a function of traffic load. To achieve this, the service includes a custom scaling logic and monitoring capabilities. An automated monitoring framework not only triggers elastic scaling, but also a troubleshooting process which detects and analyzes anomalies, pro-actively aiding both dev and ops personnel. Such a DevOps-inspired approach enables a shorter update cycle to the running service. We highlight multiple learnings yielded throughout the prototype realization, focussing on the functional areas of service decomposition and scaling; programmable monitoring; and automated troubleshooting. Such practical insights will contribute to solving challenges such as agile deployment and efficient resource usage in future NFV platforms.

Next generation network services will be realized by NFV-based microservices to enable greater dynamics in deployment and operations. Here, we present a demonstrator that realizes this concept using the NFV platform built in the EU FP7 project UNIFY. Using the example of an Elastic Router service, we show automated deployment and configuration of service components as well as corresponding monitoring components facilitating automated scaling of the entire service. We also demonstrate automatic execution of troubleshooting and debugging actions. Operations of the service are inspired by DevOps principles, enabling quick detection of operational conditions and fast corrective actions. This demo conveys essential insights on how the life-cycle of an NFV-based network service may be realized in future NFV platforms.

This paper discusses the benefits of applying software defined networking (SDN) to circuit based transport networks. It first establishes the need for SDN in the context of transport networks. This paper argues that the use of SDN in the transport layers could be the enabler for both packet-optical integration and improved transport network applications. Then, this paper proposes extensions to OpenFlow 1.1 to achieve control of switches in multi-technology transport layers. The approach presented in this paper is simple, yet it distinguishes itself from similar work by its friendliness with respect to the current transport layer control plane based on generalized multiprotocol label switching (GMPLS). This is important as it will enable an easier and gradual injection of SDN into existing transport networks. This paper is completed with a few use case applications of SDN in transport networks.

The assumption of routing symmetry is often embedded into traffic analysis and classification tools. This paper uses passively captured network data to estimate the amount of traffic actually routed symmetrically on a specific link. We propose a Flow-Based Symmetry Estimator (FSE) -- a set of metrics to assess symmetry in terms of flows, packets and bytes, which disregards inherently asymmetrical traffic such as UDP, ICMP and TCP background radiation. This normalized metric allows fair comparison of symmetry across different links. We evaluate our method on a large heterogeneous dataset, and confirm anecdotal reports that routing symmetry typically does not hold for non-edge Internet links, and decreases as one moves toward core backbone links, due to routing policy complexity. Our proposed metric for traffic asymmetry induced by routing policies will help the community improve traffic characterization techniques and formats, but also support quantitative formalization of routing policy effects on links in the wild.

The dominating Internet protocols, IP and TCP, allow some flexibility in implementation, including a variety of optional features. To support research and further development of these protocols, it is crucial to know about current deployment of protocol specific features and accompanying anomalies. This work is intended to reflect the current characteristics of Internet backbone traffic and point out misbehaviors and potential problems. On 20 consecutive days in April 2006 bidirectional traffic was collected on an OC-192 backbone link. The analysis of the data provides a comprehensive summary about current protocol usage including comparisons to prior studies. Furthermore, header misbehaviors and anomalies were found within almost every aspect analyzed and are discussed in detail. These observations are important information for designers of network protocols, network application and network attack detection systems.1..