Marco Liebsch

Cost analysis of initial deployment strategies for virtualized mobile core network functions

A virtualized network infrastructure is composed of multiple virtualized network functions (VNF) interconnected by well defined interfaces, and thus forming a VNF-graph. The initial deployment of such a VNF-graph inside a data center (DC) is a complex task with multidimensional aspects compared to deploying a single VNF that may represent a single network function. The problem space becomes more complex when each VNF is further decomposed into multiple VNF components (VNFC), where each VNFC embodies a subset of network functions attributed to the respective VNF. The challenge is to ensure that the deployment strategy meets the intra-functional constraints between the multiple VNFCs constituting the VNF-graph while ensuring service, performance and operational integrity, and also ensures optimal utilization of the underlying resources of the DC infrastructure (DCI). In this article we analyze the cost incurred by two “constraint-based heuristically applied” initial VNF/VNFC deployment strategies with reference to a virtualized mobile network infrastructure providing EPCaaS (evolved packet core as a service) while taking into consideration functional and administrative constraints. The cost of deployment is measured in terms of the utilization of DC infrastructure resources such as compute and networking. We also present the discussion in view of the ETSI NFV MANO framework, undergoing standardization, that is responsible for management and orchestration of NFV systems including VNF deployment.

Preliminary Binding: An Extension to Proxy Mobile IPv6 for Inter-Technology Handover

The Internet Engineering Task Force (IETF) recently approved the Proxy Mobile IPv6 standard for network-based localized mobility management. Unlike host-based mobility management, the network handles mobility signaling on behalf of mobile nodes in Proxy Mobile IPv6, i.e., the mobile nodes are not involved in mobility management, hence have no control on handover-related signaling. The current specification of Proxy Mobile IPv6 defines basic operations for registration, deregistration, and tunnel management. As mobile nodes have no control on mobility management, the timing for handover signaling is not synchronized with the mobile nodes ability to send and receive packets on the handover target link. This turns out to be an issue for mobile nodes being equipped with multiple network interfaces and performing handover between these access technologies (inter-technology handover), as the configuration of the target network interface and the associated link takes time. In this work, we investigate technical issues that occur during an inter-technology handover in Proxy Mobile IPv6. We demonstrate through experimental performance evaluation that an inter-technology handover in Proxy Mobile IPv6 can cause considerable handover delay and packet loss. We propose an efficient extension to Proxy Mobile IPv6 to eliminate delay and packet loss during an inter-technology handover. We demonstrate the effectiveness of the proposed extension through an experimental performance evaluation.

Software Defined Networking to support IP address mobility in future LTE network

The existing LTE network architecture dose not scale well to increasing demands due to its highly centralized and hierarchical composition. In this paper we discuss the major modifications required in the current LTE network to realize a decentralized LTE architecture. Next, we develop two IP address mobility support schemes for this architecture. The proposed solutions can handle traffic redirecting and seamless IP address continuity for the nodes moving among the distributed anchor points in a resource efficient manner. Our approaches are based on the SDN (Software Defined Networking) paradigm which is also one of the most important candidate technologies to realize 5G mobile networks. We extend the NS3-LENA simulation software to implement a decentralized LTE network as well as the proposed IP mobility support schemes. The evaluation results show that the proposed solutions efficiently fulfill the functionality and performance requirements (e.g., latency and packet loss) related to mobility management.

Double-NAT Based Mobility Management for Future LTE Networks

In this paper we discuss the major modifications required in the current LTE network to realize a decentralized LTE architecture and develop a novel IP mobility management solution for it. The proposed solution can handle traffic redirecting and IP address continuity above the distributed anchor points in a scalable and resource efficient manner. Our approach is based on the NAT (Network Address Translation) mechanism, which is a well- known and widely used procedure in the current Internet. We extend the NS3-LENA to implement a decentralized LTE network as well as the proposed scheme. The evaluation results show that the proposed solution efficiently fulfills the functionality and performance requirements (e.g.,latency and signaling load) related to the mobility management.

Simultaneous Binding Extension to Proxy Mobile IPv6 as Service Enabler for Multi-Mode Mobile Devices

Various standardization development organizations consider network-based mobility management in future mobile communication networks to complement host-based mobility management. Proxy mobile IPv6 is currently being standardized to suit basic requirements of network-based mobility management, such as no-host involvement in the location update procedure. In this paper, we want to motivate advanced operation of multi-mode mobile terminals, which attach to a proxy mobile IPv6 enabled network through multiple network interfaces simultaneously. We propose extensions to proxy mobile IPv6 enabled networks to allow simultaneous operation of a devices multiple interfaces, which have the same IPv6 address configured, while being registered with a single mobility anchor. Along with a description of these extensions, this paper comprises results of measurements we could perform in a real test-bed to show the performance gain of two target scenarios for flow distribution and bandwidth aggregation.