Emerging paradigms, such as edge computing, require the geographical distribution of small-scale data centers that will use network functions virtualization (NFV) to provide new services with stringent demands related to throughput, latency, cost, innovation, and efficient orchestration. To tackle these demands, this paper proposes VirtPhy, a fully programmable architecture for NFV orchestration in edge data centers, based on server-centric topologies, software-defined networking, software switches, distributed service chaining, and source routing. A proof-of-concept is implemented in a data center testbed using OpenStack cloud platform in a hypercube topology. The results show its orchestration mechanisms can efficiently provision NFV service requests by steering traffic through a sequence of virtualized network functions in a server-centric topology.
21 March 2022 in IEEE Transactions on Network and Service Management
Innovative traffic engineering functions and services require disrupting routing and forwarding mechanisms to be performed with low overhead over complex network topologies. Source routing (SR) is a prominent alternative to table-based routing for providing the needed expressiveness and agility by reducing the number of network states. This work proposes the M-PolKA, a topology-agnostic multipath source routing scheme and orchestration architecture for reliable communications, which explores special properties from the Residue Number System (RNS) polynomial arithmetic. A P4-based proof-of-concept is experimentally demonstrated using emulated and hardware prototypes. Also, use cases for revealing M-PolKA’s functionalities are tested in different scenarios in order to address problems, such as communication reliability improvement, agile path migration and fast failure reaction. Finally, low overhead for extra functionalities is observed when RNS-based SR is compared to traditional routing approaches.
At the verge of the launch of the first commercial fifth generation (5G) system, trends in wireless and optical networks are proceeding toward increasingly dense deployments, supporting resilient interconnection for applications that carry higher and higher capacity and tighter latency requirements. These developments put increasing pressure on network backhaul and drive the need for a re-examination of traditional backhaul topologies. Challenges of impending networks cannot be tackled by star and ring approaches due to their lack of intrinsic survivability and resilience properties, respectively. In support of this re-examination, we propose a backhaul topology design method that formulates the topology optimization as a graph optimization problem by capturing both the objective and constraints of optimization in graph invariants. Our graph theoretic approach leverages well studied mathematical techniques to provide a more systematic alternative to traditional approaches to backhaul design. Specifically, herein, we optimize over some known graph invariants, such as maximum node degree, topology diameter, average distance, and edge betweenness, as well as over a new invariant called node Wiener impact, to achieve baseline backhaul topologies that match the needs for resilient future wireless and optical networks.
16 April 2024 in IEEE Transactions on Network and Service Management
This paper presents a scalable and efficient solution for secure network design that involves the selection and verification of network paths. The proposal addresses the challenges related to compliance policies by introducing a Proof-of-Transit (PoT) feasible implementation for path-aware programmable networks. Our approach relies on i) a source routing mechanism based on a fixed routeID representing a unique identifier per path, which serves as a key for PoT lookup tables; ii) the "in situ" that allows to collect telemetry information in the packet while the packet traverses a path. The former enables path selection with policy at the edge, while the later allows to perform path verification without extra probe-traffic. A P4 programmable language prototype demonstrates the effectiveness of this approach to protect against deviation attacks with low overhead. The results show its scalability considering the protocol overhead as the path length increases; a significant reduction in network’s forwarding state for fat-tree topologies depending on the workload per path (flows/path). Finally, experimental results show a RTT comparison evaluation, the impact of PoT computation, protection to path deviation and seamless path migration keeping flow protection.
This paper proposes, implements, and evaluates VirtPhy, a novel approach to build small-scale data centers network infrastructure for network functions virtualisation (NFV). VirtPhy is fully programmable to respond to NFV stringent demands related to throughput, latency, cost, rapid innovation, and efficient orchestration. An 8-node testbed demonstrates its key enabling mechanisms, which are programmed to jointly make the most of the available physical infrastructure.
This paper proposes KAR (Key-for-Any-Route), a new intra-domain resilient routing system in which edge-nodes set a route ID to select any existing route as an alternative to safely forward packets to their destination. In KAR routing system, a route is defined as the remainder of the division between a route ID and a set of switch IDs along the path(s) between a pair of nodes. KAR-enabled switches explore the existing routes by using special properties of Residue Number System as our encoding technique. Packets are deviated from the faulty link (liveness condition) with routing deflections. Deflected packets are guided to their original destination due to resilient forwarding paths added to the route ID. Three deflection methods are discussed along emulation experiments. Results show that KAR efficiently allows deflected packets to automatically reach their destination, imposing a bound on packets disordering measured in TCP throughput.