James P.G. Sterbenz

The GpENI testbed: Network infrastructure, implementation experience, and experimentation

The Great Plains Environment for Network Innovation (GpENI) is an international programmable network testbed centered initially in the Midwest US with the goal to provide programmability across the entire protocol stack. In this paper, we present the overall GpENI framework and our implementation experience for the programmable routing environment and the dynamic circuit network (DCN). GpENI is built to provide a collaborative research infrastructure enabling the research community to conduct experiments in Future Internet architecture. We present illustrative examples of our experimentation in the GpENI platform.

Towards Resilient Networks Using Programmable Networking Technologies

Resilience is arguably the most important property of a networked system, one of the three quality of service (QoS) characteristics along with security and performance. Now that computer networks are supporting many of the applications crucial to the success of the emerging Information Society --- including business, health care, education, science, and government --- it is particularly important to ensure that the underlying network infrastructure is resilient to events and attacks that will inevitably occur. Included in these challenges are flash crowd events, in which servers cannot cope with a very large onset of valid traffic, and denial of service attacks which aim to damage networked system with malicious traffic. In this paper, we outline the case for mechanisms to deal with such events and attacks, and we propose programmable networking techniques as the best way ahead, illustrated by a flash crowd example.

Analysing GeoPath diversity and improving routing performance in optical networks

With the increasing frequency of natural disasters and intentional attacks that challenge telecommunication networks, vulnerability to cascading and regional-correlated challenges is escalating. Given the high complexity and large traffic load of optical networks, these correlated challenges cause substantial damage to reliable network communication. In this paper, we propose a network vulnerability identification mechanism and study different vulnerability scales using real-world optical network data. We further propose geographical diversity and incorporate it into a new graph resilience metric cTGGD (compensated Total Geographical Graph Diversity), which is capable of characterising and differentiating resiliency levels among different optical fibre networks. It is shown to be an effective resilience level indicator under regional network challenges or attacks. We further propose two heuristics for solving the path geodiverse problem (PGD) in which the calculation of a number of geographically separated paths is required. Geodiverse paths can be used to circumvent physical challenges such as large-scale disasters in telecommunication networks. We present the GeoDivRP routing protocol with two new routing heuristics implemented, which provides the end nodes with multiple geographically diverse paths. Our protocol demonstrates better performance compared to OSPF when the network is subject to area-based challenges. We have analysed the mechanism by which the attackers could use to maximise the attack impact with a limited budget and demonstrate the effectiveness of restoration plans.

Disciplines and measures of information resilience

Communication networks have become a fundamental part of many critical infrastructures, playing an important role in information delivery in various failure scenarios triggered e.g., by forces of nature (including earthquakes, tornados, fires, etc.), technology-related disasters (for instance due to power blackout), or malicious human activities. A number of recovery schemes have been defined in the context of network resilience (with the primary focus on communication possibility in failure scenarios including access to a particular host, or information exchange between a certain pair of end nodes). However, because end-users are becoming more and more interested in information itself (regardless of its physical location in the network), it is appropriate to complement the well-defined framework of network resilience with one that addresses information resilience, and to introduce definitions of relevant disciplines and measures, as proposed in this paper.