Magnus Karlsson

Many people and companies are betting that cloud-native networking will be the preferred way of implementing network functions in an easy and scalable way. It is based around the tenants of modularity, high availability, scalability, low-overhead networking, and ease of deployment. And a number of companies such as Google has shown that it is really possible to achieve these properties with it. But the architectural basis of cloud-native is quite different from the ones of virtualization-based NFV, but nevertheless, in many cases we continue to use the software packages that were designed for that drastically different architecture. The question is, how well does the current set of open source projects used in NFV work in a cloud-native environment and what needs to change in them in order to realize the cloud-native vision?

In this presentation, I will define what I mean with cloud-native networking and from that derive the system requirements needed to realize that vision. Based on these requirements, we can deduce a number of basic architectural properties, features and services that are needed in the system to be able to satisfy these requirements. Then I will go through the most popular open source projects such as Linux, DPDK and OVS and see how they satisfy these architectural properties and features. The main contribution of this presentation will be to show what we need to work on within these SW packages in order to realize cloud-native networking. Or maybe we need completely new SW projects to be able to achieve this.

The eXpress Data Path (XDP) is a Linux kernel feature, that have gain a lot of traction over the last couple of years. This talk is focused on how other FOSS projects can leverage XDP. How we believe XDP should be seen as a software offload for the kernel network stack.

The motivation is to plant FOSS seeds for collaboration by describing that XDP offers of facilities and capabilities. But also explain that XDP is not the magic-bullet by framing the XDP design and what layer it operates at (e.g. no de-fragmentation) and what limits XDP impose when enabled (e.g. no jumbo-frames).

In the second part of this talk we will focus on AF_XDP and how it can be leveraged by the DPDK project. AF_XDP is a new socket type introduced in Linux 4.18, that allow the XDP driver hook to deliver raw frames into userspace. This offers new opportunities for e.g. integrating with DPDK via a Poll Mode Driver (PMD) for AF_XDP.

Deep Packet Inspection (DPI) and other specialized packet processing workloads are often run in user space due to their complexity and/or specialization. With the increase of Ethernet speeds from 40, 100 to 200 Gbits/s, the need for high-speed raw Ethernet frame delivery to Linux user-space is ever increasing. In this talk, we present AFXDP (formerly known as AFPACKET V4) designed to scale to these high networking speeds through the use of true zero-copy, lock-less data structures, elimination of syscalls and other techniques, while still abiding to the isolation and security rules of Linux. AF_XDP is currently an RFC on the Linux netdev mailing list with the goal to get it accepted upstream.

In our evaluation, AFXDP provides a performance increase of up to 40x for some microbenchmarks and 20x for tcpdump compared to previous AFPACKET (raw socket) versions in Linux. To illustrate the approach, we have implemented support for Intel I40E NICs and veth, but it should hopefully be easy to port to other NICs and virtual devices as well. AFXDP is designed as an extension to the existing XDP support in Linux so that XDP enabled devices will be able to use this. We also show how SW networking libraries and SDKs such as DPDK can benefit from AFXDP to achieve increased robustness, ease-of-use and HW independence.

Name: Magnus Karlsson, Intel, Stockholm, Sweden

  Björn Töpel, Intel, Stockholm, Sweden

Bio Magnus Karlsson:

Magnus Karlsson has worked with low-level SW and microprocessor design for most of his life. Started in academia as a post-doc, but for the past 11 years he has been working "in the real world". Currently, his main interests lie in Linux networking, telecom systems and hypervisors. He is an avid cook, skier and runner, and dreams of becoming a wine grower or beer brewer at some point in his life.

Bio Björn Töpel:

Björn Töpel has dabbled in all kinds of networking stacks, ranging from Skype's peer-to-peer stack, high-frequency trading platforms all the way down to Ethernet device drivers. For the moment, most of his time is spent in the Linux kernel. He's a coffee addict, avid runner and wannabe librarian.