direkt zum Inhalt springen

direkt zum Hauptnavigationsmenü

Sie sind hier

TU Berlin

Inhalt des Dokuments


"ClowdNets are virtualized networks which can be run in parallel on top of a shared physical infrastructure. These CloudNets can have different properties (provide different security/QoS/… guarantees, run different protocols, etc.) and can be managed independently of each other. Moreover, (parts

of) a CloudNet can be migrated dynamically to locations where the service is most useful or most cost efficient (e.g., in terms of energy conservation). Depending on the circumstances and the technology, these migrations can be done live and without interrupting ongoing sessions. Furthermore CloudNets can be reprovisioned during their lifetimes to react to changing requirements or unforeseeable events.


The flexibility of the paradigm and the decoupling of the services from the underlying resource networks has many advantages; for example, it facilitates a more efficient use of the given resources, it promises faster innovations by overcoming the ossification of today's Internet architecture, it simplifies the network management, and it can improve service performance.


Currently, we address the problem of where to embed CloudNet requests, or find algorithms to migrate CloudNets to new locations (e.g., due to user mobility) taking into account the corresponding migration cost. The obtained insights are implemented in a MapReduce cluster to analyze the feasibility on real hardware. In particular the strategy to modify existing CloudNets has proven to be an interesting research question under certain consistency requirements. Moreover, the project has important economic dimensions (e.g., regarding pricing mechanisms)."

Selected Publications

Competitive and Deterministic Embeddings of Virtual Networks
Citation key EMSS-CDEVN-12
Author Even, Guy and Medina, Moti and Schaffrath, Gregor and Schmid, Stefan
Title of Book Proceedings of 13th International Conference on Distributed Computing and Networking (ICDCN '12)
Year 2012
Location Hong Kong, China
Month January
Note Best paper award
Abstract Network virtualization is an important concept to overcome the ossification of today's Internet as if facilitates innovation also in the network core and as it promises a more efficient use of the given resources and infrastructure. Virtual networks (VNets) provide an abstraction of the physical network: multiple VNets may cohabit the same physical network, but can be based on completely different protocol stacks (also beyond IP). One of the main challenges in network virtualization is the efficient admission control and embedding of VNets. The demand for virtual networks (e.g., for a video conference) can be hard to predict, and once the request is accepted, the specification / QoS guarantees must be ensured throughout the VNet¿s lifetime. This requires an admission control algorithm which only selects high-benefit VNets in times of scarce resources, and an embedding algorithm which realizes the VNet in such a way that the likelihood that future requests can be embedded as well is maximized. This paper describes a generic algorithm for the online VNet embedding problem which does not rely on any knowledge of the future VNet requests but whose performance is competitive to an optimal offline algorithm that has complete knowledge of the request sequence in advance: the so-called competitive ratio is, loosely speaking, logarithmic in the sum of the resources. Our algorithm is generic in the sense that it supports multiple traffic models, multiple routing models, and even allows for nonuniform benefits and durations of VNet requests. Concretely, the routing models considered in this paper include: multipaths, single paths, and tree routing. For modeling traffic, we study the customer-pipe model, the hose model, and a new traffic model, called aggregate ingress model, that is well suited for modeling multicasts and multi-party video conferences.
Link to publication Download Bibtex entry

Zusatzinformationen / Extras

Quick Access:

Schnellnavigation zur Seite über Nummerneingabe

Auxiliary Functions