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Evolving our Software Stack – The Inside Story

April 4, 2016 - 18 Comments

Guest blogger: Suresh Sangiah, Sr. Director, Enterprise Networking Group 

Suresh leads the effort to reinvent the software stack that powers Cisco’s enterprise network portfolio. He spends his (long) days pushing the envelope on the infrastructure and networking technology needed to influence and lead the transformation of enterprises of the future.

Customers worldwide have been using Cisco’s Enterprise Networking portfolio of routers, switches, access points and management systems to solve their networking needs for over three decades. And for the most part this has been an excellent win-win partnership that has proven the test of time.

As a member one of the engineering groups that develop these products I am proud that we have consistently led the networking industry by delivering breakthrough products and technologies that combine innovation with a healthy dose of reliability. We have been able to stay ahead by embracing the mantra that the only constant in this ever-accelerating technology landscape is change.

And so, now, we march towards the next big change in networking – a software-driven network. Perhaps, the biggest change in a decade. And part of this change includes an evolution of the Cisco IOS.


The software for the Enterprise Networking portfolio has its roots in Cisco’s IOS software stack, which was modernized in 2008 with IOS XE that first shipped on the ASR1000 series of routers.  Our enterprise networking engineering team has now been working for over two years to lead the charge in evolving IOS XE to the next level to meet the needs of today’s enterprise networks encompassing routing, switching, wireless and also IoT.   This evolved IOS XE will accelerate IT’s ability to embrace the Cisco Digital Network Architecture and prepare the network for the agility, simplicity and security demanded by the new digital era. It will make the enterprise network ready for a controller-driven, open and extensible future that will ease and simplify network operations by allowing programmability and automation.  This is achieved in the evolved IOS XE with a technology leap in the software stack while building on the excellent foundational capabilities already present in IOS and IOS XE.

There are three main benefits that these IOS XE enhancements offer:

  1. Consistency: By delivering a common software base across the entire enterprise networking portfolio, customers can experience the benefits of consistency of capabilities, validations and operations network-wide. Evolved IOS XE delivers on that demand even as it enables significant new operational and serviceability capabilities to reduce the time to deploy while driving down the costs of running the network.
  2. Open and extensible. By offering open, north-bound interfaces at device and controller layers, IOS XE enhancements allow for easier and more sustainable programmability and automation. This allows much better and deeper integration with the Cisco APIC-EM controller, and development of better, more impactful controller-based applications.
  3. Resiliency, scale and performance. The high availability and resiliency capabilities across the entire portfolio will be advanced in a consistent manner along with improvements in scale and performance made possible by the technological evolution of the existing software for future needs.

In an upcoming series of blog posts, senior engineers working on the evolved IOS XE software stack will go under the hood on how Cisco is bringing enterprise networking into a new age and enabling the outcomes our customers are looking for with their mission-critical enterprise networks.

In the meantime you can learn more about evolved IOS XE here. I look forward to hearing what you think about these developments.

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  1. Thanks Suresh. Can you explain or point to any other article that explains how the evolved IOS-XE and Polaris fit together?

  2. Suresh, it is like you were standing next to me during a recent conversation with our director. I was explaining the advantages of single software platform for management and reliability, as well as the speed we can now integrate new technologies into our enterprise. IOS-XE is a great game changer in our environment and I look forward to moving SDN to the edge ASAP.

    • Indeed Peter. Getting all the enterprise platforms onto the common evolved IOS XE software stack from a single release train will be key to enable and accelerate the necessary transformation of enterprise networking. It is full steam ahead!

  3. You must participate in a contest for probably the greatest blogs on the web. I will suggest this site!

  4. Thanks for the concise write-up. Cisco is definitely taking it to the new level: IoT friendly and Controller-ready architectures. Way to go!

  5. Way to go! Clear and crisp message. Consistency helps customers for sure, and it also increasing Cisco’s bottomline with maximum reuse and development efficiency. Enhancing programmability aspects on the devices is improving provisioning scalability significantly by avoiding a lot of patch up work that is being done on the controllers today and will help a lot of SDN usecases.

    • Thanks Bhaskar. The programmability and automation capabilities via the northbound interfaces from the network devices that evolved IOS XE will enable will in turn enable unprecedented levels of agility in the operation of enterprise networks.

  6. Great post Suresh. Thanks for sharing.
    The team has laid a good foundation for the evolution of IOS and IOS XE with Polaris by providing a data model driven architecture and Open APIs. Its exciting to embark on the next phase of this journey with more focus on automation of network configurations/operations and deployment. Also wonderful to read the white paper with the direction on cloud enablement.

  7. Nice article Suresh. I was asking around if there was anyone thinking about adding the APIC agent on our XE and XR portfolio last week and I see this blog 🙂 This will definitely help have a consistent customer story in the DC all the way to the DCI portion. I wish we can get the XR part going as well..

  8. Open north bound interfaces at device is becoming a popular trend in networking. Standardization effort on these aspects will defiantly boosts the Cisco’s market cap in in major segments. Thanks for the nice blog Sure , waiting for your next one 🙂

    • Thanks Shivaji. Do look out for the additional blog posts coming next authored by the lead engineers on evolved IOS XE project who will go into some detail on the technology driving the transformation.

  9. Great Article Suresh! good summary and great introduction

  10. Very nicely written, Suresh ! Couldn’t have agreed more. Having a consistent IOS XE running across enterprise switches small and large would be a BIG enabler for innovative approaches to build, operate, monitor and ‘utilize’ the network. Exciting times are ahead in this journey to SDN-ize the enterprise networks.

    • That’s exactly right, Parag. Getting the evolved IOS XE software stack with its forward looking capabilities across the entire enterprise portfolio as we are poised to do now will provide the consistent software base with which to drive the next phase of the transformation of enterprise networking.

  11. Nice article Suresh, also with the upcoming URSA controller, it should help customers to orchestrate configuration and policies on the network seamlessly.