SD-WANWhat kind of Internet would we design today if we were to start from scratch using what we now know?
In 2007, attempts to answer this question at Stanford University [1] led to a project by networking gurus and experts to analyze the present and future of IP networks.

At the time, the mass mobile internet era was beginning; in fact, that very same year and barely twenty minutes from the university, a product came along that would change everything – the first iPhone. The project was called Clean Slate and tried to find answers to two main questions: First…“With what we know today, if we were to start again with a clean slate, how would we design a global communications infrastructure?”. Second, “How should the Internet look in upcoming 15 years?”.
The project gained considerable importance; as of 2007, it attracted participation from leading companies like Cisco and NTT, and in 2008, the project’s laboratories were sponsored to the tune of millions of dollars by the likes of Deutsche Telekom and NEC, with other high-level participants (such as Google and China Mobile) incorporated later.

Clean State: The origins

Investigators began by analyzing IP network and Internet performance in both their current and future context. It’s peculiar that the IP protocol, almost a chance discovery since it was developed to solve a specific problem, ended up unseating other more general architectures such as ISDN or ATM, conceived as global networks; yet many great discoveries have been made by chance – think of penicillin or radioactivity.
But let’s get back to the project, which finds that a factor in the IP protocol’s success – consisting in sharing routing knowledge and decision making among all network nodes – was on its way to becoming a deadly cancer, difficult to treat for the network. The reason for this is that each of the thousands of nodes in the network needs to be programmed with a complex proprietary syntax, with a consequent impact on network management.
From here, the investigators attempt to answer the initial question. What kind of network would we develop today based on what we’ve learned? And the answer, as often happens in trying to think big and bring order, is simple: simplicity. Converting today’s complex closed networks into simple programmable networks is core to the evolution of IP networks. But how to go about doing this? The answer lies in dedicating the network to simple data transport tasks – which is the ultimate goal of a network – and centralizing network management in a single central point. This allows the nodes in the network to be basic programmable elements controlled from a centralized point that unifies network intelligence at the same time as it simplifies it. The idea is not new; separating the control and data planes was done in the telephone network in the 80s when Signaling System number 7 (SS7) was implemented, and in the IP network, similar initiatives were already in place (for example, RFC 3746 “forwarding and Control Element Separation (ForCES)”) from the year 2004.

From Clean State Project to SDN and SDWAN

In any event, the Clean Slate project can be considered the starting point for the decoupling of the control and data planes in IP networks, giving rise to the software-defined (SD) architectures, implying that a network’s intelligence – understood as defining network topology and routing decisions – resides in a central control point developed in software rather than being distributed to each and every hardware element making up the network.
In 2012, five years after its start, the project is broken down into a number of subprojects, one of which involves developing software-defined networking (SDN) architectures and the OpenFlow protocol as a communication method between the control element and the network devices. At this point, the Clean Slate project ceases its activities and the Open Network Foundation (ONF) picks up the baton of defining, developing and standardizing these networks.
SDN is currently a mature architecture in the field of data centers, but it doesn’t scale well in WAN environments, which require overlay strategies and greater autonomy for network devices. An SD-WAN architecture in these environments helps meet these new requirements while providing the necessary dissociation of data and control planes demanded of these new networks.
Teldat is committed to continuous evolution and helping our customers by offering innovate, effective and trend-setting solutions. Teldat’s integrated SD-WAN solution comprises both network devices that facilitate the evolution from traditional networks to SD-WAN, and a central control element for a simple yet powerful means of deploying software-defined WAN networks.

Reference: [1] Article in Campus Technology 12/08/08

About the author

Marcel GilMarcel Gil
graduated in Telecommunication Engineering and Master in Telematics (Polytechnic University of Catalunya), is a SD-WAN Business Line Manager at Teldat.

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