The Disaggregated NOS is the cornerstone of Technology Innovation and New Services

Disaggregated Networking has now become a reality in large service provider networks, driven by the need to innovate and bring additional revenues through new network-based services. We review the key ingredients that makes a NOS an ideal candidate to deliver key routing functions and bring deep into the network the much needed innovation.

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Six years ago, Jon Donovan, the Chief Strategy Officer and Group President of AT&T Technology and Operations stated in a fireside chat in public that Whitebox networking would be the single biggest change in the Telecom industry with the most profound impact on how we design, build and operate networks.

Interestingly, the poll conducted in the public attending the discussion gave zero votes for Whitebox networking.

ExaNOS Datasheet

Last year, AT&T announced that it had reached the critical milestone of 75% of its network being virtualized, using standard Whitebox hardware running software that reproduces most networking functions. From core to the edge, AT&T’s networks, which deliver services to almost 200 million customers, are running on Whitebox.

Why has AT&T been so relentlessly driven all these years to transform its networks into a Software Defined Networking platform?

As Jon Donovan bluntly put it:” (It’s a matter of) survival”.

Customer expectations on the one-hand and the advent of “non-traditional” Other The Top (OTT) competitors on the other hand created a mega pressure on Communication Service Providers (CSP) to deliver innovative services, fast, and in a profitable manner to ensure a growing bottom line and continuous investments in the network.

The genius of Jon Donovan and AT&T as a whole, was to recognize that innovation would not thrive in the old traditional networking model, where a handful of vendors such as Cisco and Juniper would lock you in, by providing closed and proprietary systems which are unable to communicate with the flourishing and ever-growing ecosystem of enterprise and consumer applications. The “old” way does not work any longer. It is ok to push packets from one router to another, but the network has to be in sync with the upper layers, understand in real-time the requirements of user applications and allocate the necessary network resources to ensure an optimal quality of experience.

This is the ultimate objective of Whitebox Networking (otherwise called Open or Disaggregated Networking).

At the heart of open networking lies the Network Operating System, the cornerstone of innovation, which enables any third-party applications to communicate with the network and send the critical information which ensures the network delivers the appropriate bandwidth, roundtrip and jitter times for an optimal and constant end-user quality of service.

The role of the open Network Operating System is to coordinate all the routing decisions taking place on the control plane and effect these decisions on the data plane to forward traffic using the correct routes. But there is a newer role of the Network Operating System, which is almost non-existent in traditional networking. It is about changing the network into a “business-aware” entity, understanding the context in which traffic is forwarded from point A to point B and applying the rules that will guarantee the best conditions for all applications.

These decisions need to happen at scale, as nowadays tens of Terabits per seconds of traffic are continuously flowing from the peering points all the way down to the access networks through the Core.

For this vision to become a reality, there are a few requirements on the Network Operating System:

  • It has to provide a wide array of protocols and features
  • Its core software architecture must mimic cloud platforms architecture
  • It needs to be open
  • It has to be fully secure

ExaNOS, Exaware’s advanced open Network Operating System matches all of these requirements. We are going to discuss these points in the following lines.

ExaNOS Datasheet

Wide array of protocols and features

CSPs’ networks are incredibly complex in nature. They run a large set of protocols, above which many features are applied, to ensure that network traffic is handled in the right way and fully secure.

Internal networks run an Interior Gateway Protocol, usually OSPF or IS-IS. The exterior Gateway Protocol is traditionally BGP. You might also need to run multicast in some parts of the network, especially if you stream video. You also need to deal with IPv4 and IPv6 addresses. You need to filter traffic on your peering points and therefore need scalable Access Control Lists or even BGP-Flowspec if you want to automate DDoS attack filtering.

There is much more to cover, but the above gives an idea of the complexity.

ExaNOS includes all of these protocols and features, to allow you to run the same Network Operating System across your entire estate.

A core software architecture that mimics cloud platforms architecture

Cloud elasticity, the ability to scale up and down cloud resources, is also a key performance factor in Open Networking.

Hardware resources need to be available, but the ability to coordinate all protocols and features, apply instant routing decisions and quality of service priority queuing at scale requires a flexible and robust Network Operating System. Cloud Computing has demonstrated its ability to scale almost infinitely. The new open Network Operating System needs to replicate the same architecture; distributed internal processes which focus on a few tasks and work concurrently to deliver the traffic scale required at any point in time.

ExaNOS, which ran in Tier-1 production networks at Comcast and NTT embeds in its core a distributed architecture, which can be replicated on every single line card of large hardware routers.

The internal “fault protection” mechanism handles any exception to isolate it from other processes and ensure a nonstop routing traffic.

ExaNOS can scale up to hundreds of Terabits per seconds, running the full gamut of protocols and features without budging.

The need to be Open

The number one critic of the old networking model of Cisco and Juniper is its closed architecture. Every time you buy a new router, you need to buy and pay for the Network Operating System once again, you cannot reuse the licenses you bought in the past with a different hardware. It includes tons of features you do not necessarily need but are there for legacy purposes. However, the interesting features such as L2/L3 VPN incur an extra charge, based on the bandwidth required.

The reason why IP networks have not innovated since the nineties is because traditional vendors have purposefully kept their “walled gardens” completely closed. You get, at best, the parameters available in the SNMP MIB, more aimed at monitoring purposes.

When it comes to deeply embed third-party applications in the network, accessing the core functions and parameters of the Network Operating System becomes key. You do that by providing a northbound interface to the operating system, so that your applications can both read routing parameters and modify them at will.

Let’s discuss a practical example.

DDoS mitigation is a fundamental network security service, which could take a massive advantage from the information contained in the peering routers and could also use their filtering capabilities to keep malicious traffic outside of the network.

Although there are existing solutions, which use BGP Flowspec, their capacity to scale to thousands of simultaneous filters is somewhat limited, because the Flowspec interface has its limits and also the routers themselves can only handle a few hundred filters at best.

With an open Network Operating System, the DDoS mitigation capability can be embedded within the router (but also kept outside of it) and become a true shield against outside attacks, with scale, accuracy and in real-time. When deployed at every peering point, the DDoS protection systems get to a new level, leaving the internal networks clean of “polluting” traffic. The DDoS identification component is able to directly communicate with the router’s Network Operating System and instruct it to block, throttle or rate limit specific source IP addresses.

Fully Secure

All of the key attributes of the open Network Operating System should not come at the expense of reliability and security. The Open nature of the disaggregated Network Operating System raises questions on the integrity of the router and by extension, of the entire network.

In an open Network Operating System, such as ExaNOS, the basic, yet fundamental features of IP routers are still present, such as AAA/TACACS+ and SSH authentication and connection methods.

Security functions, such as MD5 authentication for routing protocols is also available on ExaNOS, to ensure that established connections with external routers cannot be compromised.

Control plane ACLs protect the router from unnecessary traffic and ensure the right prioritization of routing decisions, to keep an optimal performance.

This is only a small subset of all the security features available on ExaNOS.

A new chapter of the networking industry history has begun. What many CSPs dreamt about during the past decades has now come to fruition. The fundamental building blocks of open innovation in the network are now there. Expect to see efficiency improvements in operations, using applications such as BGP routing optimization or telemetry, to identify network issues before they become customer impacting.

Revenue generating services, such as on-demand bandwidth and VPN services, personal DDoS mitigation protection per business, or ultra-HD video services where the network guarantees the Quality of Experience now becomes a reality.

The era of Smart Networks has come in.

Interested to know more? Contact us at to book a demo.

ExaNOS Datasheet



Here is what we will cover in 45 minutes:

Learn how Open Networking can give you the power to change your network to bring fast new services to the market, without compromising on quality and scalability.

Discover the various applications that can benefit from Exaware Open Networking Solutions.

See how easy it is to configure an Exaware Router.



Here is what we will cover in 45 minutes:

Learn how Open Networking can give you the power to change your network to bring fast new services to the market, without compromising on quality and scalability.

Discover the various applications that can benefit from Exaware Open Networking Solutions.

See how easy it is to configure an Exaware Router.

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