Julius Schulz-Zander

Network Function Virtualization (NFV) is emerging as one of the most innovative concepts in the networking landscape. By migrating network functions from dedicated middleboxes to general purpose computing platforms, NFV can effectively reduce the cost to deploy and to operate large networks. However, in order to achieve its full potential, NFV needs to encompass also the radio access network allowing Mobile Virtual Network Operators to deploy custom resource allocation solutions within their… Mehr anzeigen

Network Function Virtualization (NFV) is emerging as one of the most innovative concepts in the networking landscape. By migrating network functions from dedicated middleboxes to general purpose computing platforms, NFV can effectively reduce the cost to deploy and to operate large networks. However, in order to achieve its full potential, NFV needs to encompass also the radio access network allowing Mobile Virtual Network Operators to deploy custom resource allocation solutions within their virtual radio nodes. Such requirement raises several challenges in terms of performance isolation and resource provisioning. In this work we formalize the Virtual Network Function (VNF) placement problem for radio access networks as an integer linear programming problem and we propose a VNF placement heuristic. Moreover, we also present a proof-of-concept implementation of an NFV management and orchestration framework for Enterprise WLANs. The proposed architecture builds upon a programmable network fabric where pure forwarding nodes are mixed with radio and packet processing nodes leveraging on general computing platforms. Weniger anzeigen

The quickly growing demand for wireless networks and the nu- merous application-specific requirements stand in stark contrast to today’s inflexible management and operation of WiFi networks. In this paper, we present and evaluate OpenSDWN, a novel WiFi architecture based on an SDN/NFV approach. OpenSDWN exploits datapath programmability to enable service differentiation and fine-grained transmission control, facilitating the prioritization of critical applications. OpenSDWN implements… Mehr anzeigen

The quickly growing demand for wireless networks and the nu- merous application-specific requirements stand in stark contrast to today’s inflexible management and operation of WiFi networks. In this paper, we present and evaluate OpenSDWN, a novel WiFi architecture based on an SDN/NFV approach. OpenSDWN exploits datapath programmability to enable service differentiation and fine-grained transmission control, facilitating the prioritization of critical applications. OpenSDWN implements per-client virtual access points and per-client virtual middleboxes, to render network functions more flexible and support mobility and seamless migration. OpenSDWN can also be used to out-source the control over the home network to a participatory interface or to an Internet Ser- vice Provider. Weniger anzeigen

Software-Defined Networking (SDN) has received, in the last years, significant interest from the academic and the industrial communities alike. The decoupled control and data planes found in an SDN allows for logically centralized intelligence in the control plane and generalized network hardware in the data plane. Although the current SDN ecosystem provides a rich support for wired packet–switched networks, the same cannot be said for wireless networks where specific radio data-plane… Mehr anzeigen

Software-Defined Networking (SDN) has received, in the last years, significant interest from the academic and the industrial communities alike. The decoupled control and data planes found in an SDN allows for logically centralized intelligence in the control plane and generalized network hardware in the data plane. Although the current SDN ecosystem provides a rich support for wired packet–switched networks, the same cannot be said for wireless networks where specific radio data-plane abstractions, controllers, and programming primitives are still yet to be established. In this work, we present a set of programming abstractions modeling the fundamental aspects of a wireless net- work, namely state management, resource provisioning, network monitoring, and network reconfiguration. The proposed abstractions hide away the implementation details of the underlying wireless technology providing programmers with expressive tools to control the state of the network. We also present a Software- Defined Radio Access Network Controller for Enterprise WLANs and a Python–based Software Development Kit implementing the proposed abstractions. Finally, we experimentally evaluate the usefulness, efficiency and flexibility of the platform over a real 802.11-based WLAN. Weniger anzeigen

With wireless technologies becoming prevalent at the last hop, today’s network operators need to manage WiFi access networks in unison with their wired counterparts. However, the non-uniformity of feature sets in existing solutions and the lack of programmability makes this a challenging task. This paper proposes Odin, an SDN-based solution to bridge this gap. With Odin, we make the following contributions: (i) Light Virtual Access Points (LVAPs), a novel programming abstraction for addressing… Mehr anzeigen

With wireless technologies becoming prevalent at the last hop, today’s network operators need to manage WiFi access networks in unison with their wired counterparts. However, the non-uniformity of feature sets in existing solutions and the lack of programmability makes this a challenging task. This paper proposes Odin, an SDN-based solution to bridge this gap. With Odin, we make the following contributions: (i) Light Virtual Access Points (LVAPs), a novel programming abstraction for addressing the IEEE 802.11 protocol stack complexity, (ii) a design and implementation for a software-defined WiFi network architecture based on LVAPs, and (iii) a prototype implementation on top of commodity access point hardware without modifications to the IEEE 802.11 client, making it practical for today’s deployments. To highlight the effectiveness of the approach we demonstrate six WiFi network services on top of Odin including load-balancing, mobility management, jammer detection, automatic channel-selection, energy management, and guest policy enforcement. To further foster the development of our framework, the Odin prototype is made publicly available. Weniger anzeigen

We present Odin, an SDN framework to introduce programmability in enterprise wireless local area networks (WLANs). Enterprise WLANs need to support a wide range of services and functionalities. This includes authentication, authorization and accounting, policy, mobility and interference management, and load balancing. WLANs also exhibit unique challenges. In particular, access point (AP) association decisions are not made by the infrastructure, but by clients. In addition, the association state… Mehr anzeigen

We present Odin, an SDN framework to introduce programmability in enterprise wireless local area networks (WLANs). Enterprise WLANs need to support a wide range of services and functionalities. This includes authentication, authorization and accounting, policy, mobility and interference management, and load balancing. WLANs also exhibit unique challenges. In particular, access point (AP) association decisions are not made by the infrastructure, but by clients. In addition, the association state machine combined with the broadcast nature of the wireless medium requires keeping track of a large amount of state changes. To this end, Odin builds on a light virtual AP abstraction that greatly simplifies client management. Odin does not require any client side modifications and its design supports WPA2 Enterprise. With Odin, a network operator can implement enterprise WLAN services as network applications. A prototype implementation demonstrates Odin's feasibility. Weniger anzeigen

Applying the concept of SDN to WiFi networks is challenging, since wireless networks feature many peculiarities and knobs that often do not exist in wired networks: obviously, WiFi communicates over a shared medium, with all its implications, e.g., higher packet loss and hidden or exposed terminals. Moreover, wireless links can be operated in a number of different regimes, e.g., transmission rate and power settings can be adjusted, RTS/CTS mechanisms can be used.

Indeed, due to the… Mehr anzeigen

Applying the concept of SDN to WiFi networks is challenging, since wireless networks feature many peculiarities and knobs that often do not exist in wired networks: obviously, WiFi communicates over a shared medium, with all its implications, e.g., higher packet loss and hidden or exposed terminals. Moreover, wireless links can be operated in a number of different regimes, e.g., transmission rate and power settings can be adjusted, RTS/CTS mechanisms can be used.

Indeed, due to the non-stationary characteristic of the wireless channel, permanently adjusting settings such as transmission rate and power is crucial for the performance of WiFi networks and brings significant benefits in the service quality, e.g., through reducing the packet loss probability. Today’s rate and power control is mainly done on the WiFi device itself. But it is rarely optimized to the application-layer demands and their diverse traffic requirements, e.g., their individual sensitivity to packet loss or jitter. Therefore, if SDN for wireless can provide mechanisms to control the WiFi-specific transmission settings on a per-slice, per-client, and per-flow level, traffic and application-aware optimizations are feasible. Weniger anzeigen

Programming a mobile network requires to account for multiple complex operations, such as allocating radio resources and monitoring interference. Nevertheless, the current Software–Defined Networking ecosystem provides little support for mobile networks in term of radio data–plane abstractions, controllers, and programming primitives. Starting from the consideration that WiFi is becoming an integral part of the 5G architecture, we present a set of programming abstractions modeling three… Mehr anzeigen

Programming a mobile network requires to account for multiple complex operations, such as allocating radio resources and monitoring interference. Nevertheless, the current Software–Defined Networking ecosystem provides little support for mobile networks in term of radio data–plane abstractions, controllers, and programming primitives. Starting from the consideration that WiFi is becoming an integral part of the 5G architecture, we present a set of programming abstractions modeling three fundamental aspects of a WiFi network, namely state management of wireless clients, resource provisioning, and network state collection. The proposed abstractions hide away the implementation details of the underlying wireless technology providing programmers with expressive tools to control the state of the network. We also describe a proof–of–concept implementa- tion of a Software–Defined Radio Access Network controller for WiFi networks and a Python–based Software Development Kit leveraging the proposed abstractions. The resulting platform can be effectively leveraged in order to implement typical control tasks such as mobility management and traffic engineering as well as applications and services such as multicast video delivery and/or dynamic content caching. Weniger anzeigen

Not much is known today about how to reap the SDN benefits in WiFi networks-a critical use case given the increasing importance of WiFi networks. This paper presents AeroFlux, a scalable software-defined wireless network, that supports large enterprise and carrier WiFi deployments with low-latency programmatic control of fine-grained WiFi-specific transmission settings. This is achieved through AeroFlux's hierarchical design. We report on an early prototype implementation and evaluation… Mehr anzeigen

Not much is known today about how to reap the SDN benefits in WiFi networks-a critical use case given the increasing importance of WiFi networks. This paper presents AeroFlux, a scalable software-defined wireless network, that supports large enterprise and carrier WiFi deployments with low-latency programmatic control of fine-grained WiFi-specific transmission settings. This is achieved through AeroFlux's hierarchical design. We report on an early prototype implementation and evaluation, showing that AeroFlux can significantly reduce control plane traffic. Weniger anzeigen