[Symposium 2017 – #6] IPv6-centric Networking, a Crucial Rollout for Tomorrow

5 min read

Nathalie Saintuma

Sponsored article – Author: Pierre Guyot, Editor, Usbek & Rica
The symposium “New Generation of Networking Innovation and Research” Cisco – École Polytechnique 2017

constrained by the limits of IPv4, there are in effect new possibilities opening up. Far from the complexity of IPv4, the rollout of an “IPv6-centric” network (or 6CN for IPv6-Centric Networking) aims to create a global architecture made of information shared between applications, services, networks, processes, data, etc. The transition of networking to IPv6 is a major opportunity for revolutionizing the way in which content is delivered on the Internet: a priority, since in 2020 eleven billion video devices will be connected and more than 80% of IP traffic will come from video (chat videos on YouTube, of course, but also an entire episode of Game of Thrones on one’s cell phone, so warned AT&T in the beginning of 2017).

IPv6 is especially an opportunity for traffic engineering. The discussions thus deal mainly with “Segment Routing,” a routing model consisting of the transport of data that is specified at the source and able to function in an IPv6 native environment. In this model, it is the source that chooses a route and encodes it in a packet in an ordered list of segments, thus bringing decentralization by doing away with the notion of routing states for all the network nodes other than the source.

IPv6: the companies’ turn?

But first, how is it with IPv6? In July 2013, when the implementation, measured in terms of Google user IPv6 connectivity, was estimated at less than 2% of the network, it was thought that it would reach 10% at the beginning of 2016, then 18% at the beginning of 2017, and finally 50% in October 2018. At the very beginning of 2017, after having in effect 10% in January 2016, the implementation reached “only” 16.8%. The progression was slowed by a lesser rollout among companies, the opposite of professionals (65% of the traffic that “emerges” from Cisco networks is, for example, in IPv6, and the company has an IPv6-only building in San Jose in the United States). Above all, cable operators, and indeed mobile operators such as T-Mobile USA and Verizon Wireless networks are, for example, at greater than 85% in IPv6.

At the first symposium led by the PIRL in 2016, Martin Levy, in charge of networking strategy for Cloudflare, one of the main content distribution networks (CDN) and responsible for more than a third of DNS (Domain Name System) registrations in the world, had announced the migration to IPv6 of 100% of new sites registering on Cloudflare. Since then, three million previously registered other sites have migrated. The technical challenge is great: there remains to update the exchange security protocol (TLS) and to make the existence of two DNS registrations available, A (sending back an IPv4 address) and AAAA (IPv6).

Marcus Keane, network architect intern at Microsoft (Microsoft IT), says it simply: from Microsoft’s point of view it is clear that “IPv6 is the future of infrastructure.” While access suppliers are strongly committing themselves to the movement, remarks Marcus Keane, the companies, which have to deal however with the running out of available IPv4 addresses, are lagging behind for many reasons, among which the absence of a complete standardization of multihoming (necessary for a reliable connection), which the Internet Engineering Task Force (IETF), the Internet standardization organ, is working on nonetheless. For Marcus Keane, the main reason of the “lagging behind” of this rollout is based on the onerousness of managing and the increased complexity in managing a network that needs the double pile IPv4-IPv6 technique, called Dual-Stack, adopted during the transition to IPv6. His recommendation, modelled on what Microsoft uses for its network, is to take the road of “IPv6-only,” which has become a real project in the Redmond company after several years of experimentation. In front of the complexity of Dual-Stack and the strong network demands the very many devices connected to the Internet of Things will generate, testing in this area is accelerating.

“The most important thing to do today is to insure that companies rollout IPv6.” – The video interview with Marcus Keane, Principal Network Engineer at Microsoft

IPv6, a platform for innovation: the time for Segment Routing

“Without companies, there would not be any innovation,” says in substance Marcus Keane, for IPv6 also has to do with innovation! In terms of infrastructure, things are not static, says also Sam Aldrin, network architect at Google, who came to present the Zero Touch Network, a more decentralized network infrastructure in which all operations are automated, making the infrastructure more robust by decreasing human intervention on it, which are normally frequent and on multiple points.

But with IPv6 also comes Segment Routing : in face of the rampant increase in demand for data, especially linked to 5G, to video and its new formats as well as to the Internet of Things, it can in fact be a question, not of multiplying routers, but of starting from the existing infrastructure and simplifying its architecture, optimizing its performance, and reducing its cost. This is what Segment Routing proposes, which allows the traffic to be directed from any point on the network (on its components, in the data center, or at the access point level). Segment Routing is compatible with the MPLS protocol, but its philosophy from the beginning has been to stick with IPv6. Like Comcast, operators and Internet access providers, especially those advanced in the implementation of the protocol, are already fully engaged in activating the potential of IPv6 Segment Routing beyond laboratory demonstrations—and rollouts on networks have already taken place. “The industry greatly supports Segment Routing,” concludes Clarence Filsfils, author of a presentation on the subject. The Cisco engineer supports this by the evidence of a consensus being observed among providers, standardization being led by the IETF, the fact that “SR” has become the de facto SDN architecture, and finally, starting four years ago, the adoption of the technology by customers, FAI, and companies. But it is its implementation with IPv6, routing IP across a group of nodes or services represented by an IPv6 address, that stands out as a hot topic. For the SoftBank Telecom operator and its vice-president, Satoru Matsushima, “SRv6” allows, for example, the organizing of a mobile network in a simpler and more flexible way, but it also is a question of integrating it into 5G standards. The subject of virtualization, beyond virtual machines, with containers and unikernel, is also on the agenda, perhaps permitting the implementation of a “super-fluide” network.

“In four years, we have known how to insure the implementation of inter-domain routing in data centers, subways, large aggregations, and in the very framework of the network.”, The presentation of Clarence Filsfils, Cisco Fellow :