GNFC: Towards Network Function Cloudification

An increasing demand is seen from enterprises to host and dynamically manage middlebox services in public clouds in order to leverage the same benefits that network functions provide in traditional, in-house deployments. However, today's public clouds provide only a limited view and programmability for tenants that challenges flexible deployment of transparent, software-defined network functions. Moreover, current virtual network functions can't take full advantage of a virtualized cloud environment, limiting scalability and fault tolerance. In this paper we review and evaluate the current infrastructural limitations imposed by public cloud providers and present the design and implementation of GNFC, a cloud-based Network Function Virtualization (NFV) framework that gives tenants the ability to transparently attach stateless, container-based network functions to their services hosted in public clouds. We evaluate the proposed system over three public cloud providers (Amazon EC2, Microsoft Azure and Google Compute Engine) and show the effects on end-to-end latency and throughput using various instance types for NFV hosts

Distributed control in virtualized networks

The increasing number of the Internet connected devices requires novel solutions to control the next generation network resources. The cooperation between the Software Defined Network (SDN) and the Network Function Virtualization (NFV) seems to be a promising technology paradigm. The bottleneck of current SDN/NFV implementations is the use of a centralized controller. In this paper, different scenarios to identify the pro and cons of a distributed control-plane were investigated. We implemented a prototypal framework to benchmark different centralized and distributed approaches. The test results have been critically analyzed and related considerations and recommendations have been reported. The outcome of our research influenced the control plane design of the following European R&D projects: PLATINO, FI-WARE and T-NOVA

Okapi: Causally Consistent Geo-Replication Made Faster, Cheaper and More Available

Okapi is a new causally consistent geo-replicated key- value store. Okapi leverages two key design choices to achieve high performance. First, it relies on hybrid logical/physical clocks to achieve low latency even in the presence of clock skew. Second, Okapi achieves higher resource efficiency and better availability, at the expense of a slight increase in update visibility latency. To this end, Okapi implements a new stabilization protocol that uses a combination of vector and scalar clocks and makes a remote update visible when its delivery has been acknowledged by every data center. We evaluate Okapi with different workloads on Amazon AWS, using three geographically distributed regions and 96 nodes. We compare Okapi with two recent approaches to causal consistency, Cure and GentleRain. We show that Okapi delivers up to two orders of magnitude better performance than GentleRain and that Okapi achieves up to 3.5x lower latency and a 60% reduction of the meta-data overhead with respect to Cure

Overcoming TCP Degradation in the Presence of Multiple Intermittent Link Failures Utilizing Intermediate Buffering

It is well documented that assumptions made in the popular Transmission Control Protocol\u27s (TCP) development, while essential in the highly reliable wired environment, are incompatible with today\u27s wireless network realities in what we refer to as a challenged environment. Challenged environments severely degrade the capability of TCP to establish and maintain a communication connection with reasonable throughput. This thesis proposes and implements an intermediate buffering scheme, implemented at the transport layer, which serves as a TCP helper protocol for use in network routing equipment to overcome short and bursty, but regular, link failures. Moreover, the implementation requires no modifications to existing TCP implementations at communicating nodes and integrates well with existing routing equipment. In a simulated six-hop network with five modified routers supporting four challenged links, each with only 60% availability, TCP connections are reliably established and maintained, despite the poor link availability, whereas 94% fail using standard routing equipment, i.e., without the TCP helper protocol

Creating Complex Network Services with eBPF: Experience and Lessons Learned

The extended Berkeley Packet Filter (eBPF) is a recent technology available in the Linux kernel that enables flexible data processing. However, so far the eBPF was mainly used for monitoring tasks such as memory, CPU, page faults, traffic, and more, with a few examples of traditional network services, e.g., that modify the data in transit. In fact, the creation of complex network functions that go beyond simple proof-of-concept data plane applications has proven to be challenging due to the several limitations of this technology, but at the same time very promising due to some characteristics (e.g., dynamic recompilation of the source code) that are not available elsewhere. Based on our experience, this paper presents the most promising characteristics of this technology and the main encountered limitations, and we envision some solutions that can mitigate the latter. We also summarize the most important lessons learned while exploiting eBPF to create complex network functions and, finally, we provide a quantitative characterization of the most significant aspects of this technology

Node JS Performance Testing

Node JS, a server side implementation of JavaScript, has gained traction over the years, especially in newer tech startups, to be used in deployment servers. Performance testing is a set of tests intended to measure the speed and reliability of a server under various loads . This project examines performance testing applied to Node JS, design decisions of the testing environment, and quantitative analysis of server improvements made to increase performance of the server of Music Putty, a music streaming and crowdfunding startup formed at Cal Poly