Fabio Pianese

Telco clouds and Virtual Telco: Consolidation, convergence, and beyond

In this position paper we introduce Virtual Telco, a comprehensive effort to simplify the management of deployed telecommunication services by using a Cloud computing approach. The main objective of Virtual Telco is to replace the costly dedicated hardware implementing several centralized control plane functions and other services with distributed solutions that may be allocated on-demand over a pool of dependable, dynamically contracted computing and networking resources that are easy to manage. Virtual Telco relies on state-of-the-art techniques in the domains of virtualization and distributed systems to meet the challenging criteria of reliability, scalability, and timeliness required by present and future telecommunication standards and services. As a representative example of a Virtual Telco application, we propose the case of the distributed mobility management entity (MME) for next-generation LTE cellular networks.

Toward a Cloud Operating System

Cloud computing is characterized today by a hotchpotch of elements and solutions, namely operating systems running on a single virtualized computing environment, middleware layers that attempt to combine physical and virtualized resources from multiple operating systems, and specialized application engines that leverage a key asset of the cloud service provider (e.g. Googles BigTable). Yet, there does not exist a virtual distributed operating system that ties together these cloud resources into a unified processing environment that is easy to program, flexible, scalable, self-managed, and dependable. In this position paper, we advocate the importance of a virtual distributed operating system, a Cloud OS, as a catalyst in unlocking the real potential of the Cloud-a computing platform with seemingly infinite CPU, memory, storage and network resources. Following established Operating Systems and Distributed Systems principles laid out by UNIX and subsequent research efforts, the Cloud OS aims to provide simple programming abstractions to available cloud resources, strong isolation techniques between Cloud processes, and strong integration with network resources. At the same time, our Cloud OS design is tailored to the challenging environment of the Cloud by emphasizing elasticity, autonomous decentralized management, and fault tolerance.

DMME: A distributed LTE mobility management entity

DMME is a distributed architecture that implements mobility management for next-generation cellular systems. It has been designed to serve as a scalable and cost-effective drop-in replacement for the Long Term Evolution (LTE) mobility management entity (MME). DMME is an example of a flexible control plane architecture that can be deployed incrementally across operator networks: processing locality is obtained by assigning control plane events to a local DMME replica and by allowing the transparent migration of control plane state across the different replicas as the users move. We evaluate the DMME scheme via analysis and simulation under several deployment scenarios, using mobility patterns drawn from both synthetic models and traces collected in a production network. Our analysis shows that DMME can achieve performances that are comparable with a centralized, server-based infrastructure in terms of system availability and signaling delay. Furthermore, we propose and evaluate a set of heuristics based on user behavior that specify the allocation policy of DMME instances over the available replicas. We also report preliminary performance figures from our DMME prototype implementation. Our results confirm that distributed architectures are a viable choice to reliably support high-throughput, latency-sensitive control plane functions such as cellular mobility management.

dMME: Virtualizing LTE mobility management

With the convergence between phone and data networks in LTE and 4G, cellular signaling traffic is increasingly carried over IP. Control plane functions, once performed by dedicated machinery, are evolving into large-scale network applications with strict requirements on delay, availability, and processing throughput as mandated by 3GPP standards. In this paper we present dMME, a distributed architecture that implements mobility management for next-generation cellular systems. dMME is a scalable and cost-effective drop-in replacement for the LTE mobility management entity (MME). We evaluate the dMME scheme via analysis and simulation under several deployment scenarios, using mobility patterns drawn from synthetic models and from traces collected in a production network. We also report preliminary performance figures by our dMME prototype implementation. Our results confirm that distributed architectures are a viable choice to reliably support high-throughput, latency-sensitive control plane functions.

A programmable data plane for heterogeneous NFV platforms.

Network function virtualization (NFV) has recently allowed the rapid deployment of network functions. As software implementations become the main option for NFV, performance requirements call for an increased level of hardware support and acceleration. Additionally, the higher demand for flexibility and optimization also requires protocol stack customization at different layers. To fulfill these requirements, we introduce in this paper a programmable data plane (PDP) whose goals are to enable on-the-fly customization of L2-L7 stacks and to integrate both general-purpose CPUs and hardware accelerators. The PDP data plane provides a set of modular elements that the control plane instantiates and orchestrates to compose L2-L7 network functions, allowing a centralized controller to reconfigure heterogeneous network devices and manage state across network functions. We present examples of how PDP data plane modules can be used to realize different functions, such as an information-centric networking (ICN) router and an HTTP reverse proxy. Our preliminary results show that hardware acceleration provides significant benefits at negligible cost, and that careful use of modularity brings a minimal latency penalty, while providing high flexibility and reconfigurability to the network.

Network function virtualization: through the looking-glass

The fields of networking and telecommunications are presently witnessing the transition of a number of Network Function Virtualization (NFV) principles and techniques from research into practice. This survey attempts to capture the NFV phenomenon in its multi-faceted historical development over the last two decades, by answering the question “What are the main goals of NFV systems?” and by highlighting the advantages and technical limits of NFV in supporting those goals. By focusing on the whys and hows of NFV, we propose a reasoned overview of the most significant design elements of NFV as a complementary synthesis to the analytical taxonomies of papers and standards that are usually found in survey documents.

Understanding co-channel interference in LTE-based multi-tier cellular networks

Multi-tier network configurations are considered as a promising deployment mode for next-generation radio access networks. While it is believed that smaller cells (pico cells) can help offload traffic from macro cells, they also generate interference which may lead to capacity loss in the macro cell and neighboring small cells. It is therefore important for the mobile operators to understand and model what is the net effect of deploying pico cells on top of micro or macro cells. In this work, we introduce a comprehensive analytical framework for co-channel interference analysis in Long Term Evolution (LTE) multi-tier cellular networks and present preliminary simulation results. The model we describe is capable to provide practical insights to guide the deployment of multi-tier networks, and completes the studies in the literature with finer analytical details.

Orchestrating 5G virtual network functions as a modular Programmable Data Plane

The upcoming 5G architecture is expected to heavily rely on network functions implemented by software deployed on commodity hardware architectures. Multiple standardization efforts are underway to specify interfaces between virtualized and real infrastructure, and procedures for interoperability among functions. However, the practical feasibility of function implementation in such abstract and disembodied conditions is scarcely covered in the latest literature. In this paper, we argue for a Network Function Virtualization (NFV) framework that provides 5G network functions built around a modular software router model, rather than following the traditional VM-container approaches. We illustrate its advantages in enabling support for efficient processing on heterogeneous hardware and in ensuring consistency of flow/session semantics across distributed 5G data planes. Finally, we report on the state of Programmable Data Plane, our architecture to implement 5G network functions as modular pipelines orchestrated across multiple devices.

Information Centric Networks for Parallel Processing in the Datacenter

Datacenters provide an interesting environment for the deployment of information-centric networking (ICN) protocols. The innovative features of ICNs, such as network-layer caching of named data, when combined with new opportunities given by naming semantics, such as the selective forwarding of data processing queries and the on-path processing of partial replies, introduce a large degree of freedom in protocol design. The advantages provided by these features can be accentuated by an appropriate choice of underlying datacenter topologies. In this paper, we discuss the design of a Map/Reduce application protocol built according to ICN naming semantics, consider its requirements in terms of support by the networking substrate, and briefly evaluate its behavior with respect to caching and aggregation in a highly-dimensional datacenter topology.