In my last two blogs I discussed the challenges Enterprises are facing for their WAN, the differences between Enterprise needs in their LAN and WAN, and how the traditional ONF model for SDN isn't practical for the Enterprise WAN.  Let's now look at how the new Cisco ONE Enterprise Architecture can address this.

Cisco ONE Enterprise Network Architecture

The new Cisco ONE Enterprise Networks Architecture based on Cisco Open Network Environment (ONE) was introduced at InterOp Las Vegas during Rob Soderbery's keynote, with a deeper dive in a blog by Inbar Lasser-Raab  (shown in Figure 2). Briefly, the 3 layers are similar to SDN Architecture but are also vastly different in the following ways:

• Network Element Layer: The Cisco ONE Enterprise Networks Architecture is built upon a foundation of distributed intelligent and programmable network devices. As explained above, the case for an intelligent network device is strong for WAN and ONE Enterprise Networks Architecture comprises of intelligent network devices at the device layer.

• Control Layer: This is not a centralized controller function as defined by SDN. This is more of a control layer that offers the following:
  • Automated Provisioning:With automated configuration of network devices, the Cisco ONE Enterprise Networks Architecture delivers speed and ease of provisioning across the entire Enterprise network. This eliminates the per-device provisioning and vastly improves the speed and accuracy of adding new services consistently across the network.
  • Analytics:The Control Layer also offers advanced analytics across the entire Enterprise network, LANs and WAN. The real-time analytics data is available for any applications to use as well as for IT to monitor and diagnose any network issues.
• Network-Aware Application Layer:Cisco ONE Enterprise Networks Architecture enables applications and services to be network-aware by abstracting away the network in the Control Layer and making advanced network analytics available to the applications. Applications and services can now be smart about the network conditions and deliver an optimal user experience, securely, while simplifying IT operations.

How Cisco ONE Enterprise Networks Architecture enhances Enterprise WAN programmability?

• ONE Enterprise Networks Architecture is a 2-way street
  • Applications and networks are mutually aware in Cisco ONE Architecture which creates a robust ecosystem for resiliency, whereas SDN is a one-way street, with the SDN Controller centrally managing network devices, which does not scale to WAN networks for reasons explained above.
• ONE Enterprise Networks Architecture scales to WAN networks:
  • SDN Controller architecture is limited in scope to L2 networks in a single data-center whereas the Cisco ONE Enterprise Networks Architecture brings programmability to LAN and WAN networks alike.
  • Programmability in WAN networks requires intelligent network devices that have programmatic access but are free to run distributed protocols that make the network much more resilient than with centralized control.
• ONE Enterprise Networks Architecture Control Layer is simpler and agile:
  • The Control Layer does not have to reinvent complex topology control mechanisms and can easily query and maintain network wide analytics. These analytics are useful to the network-aware application layers.
  • With an SDN Controller over WAN networks, again, one reinvents the broken wheel of centralized end-to-end provisioning similar to legacy ATM circuit-switched networks. The SDN Controller complexity would be hard to manage and deploy.
• Coordination Costs
  • The suggested ONF SDN architecture implies best of breed solutions for each layer. This can increase coordination costs for enterprises as they have to integrate different vendors' solutions into a complex WAN network topology and manage network throughput requirements across all the layers. Coordinating the development and rollout of a new application between all 3 layers over the WAN can be very expensive.
  • Cisco ONE Enterprise Networks Architecture on the other hand builds upon a foundation of intelligent Cisco network devices with proven data-planes that implement complex distributed protocols. Further, a simpler control layer that allows the ease and speed of provisioning new applications and services that can be provided by 3^rdparty application developers. This increased business agility and enables enterprises to respond rapidly to new business opportunities.

Cisco ONE Enterprise Networks Architecture brings the networks and applications closer together across the entire Enterprise network. It is all about creating a feedback loop between the applications and the network and allowing the applications to control the network at many levels. Cisco ONE Enterprise Networks Architecture provides the tools to make the Enterprise network programmable both in data-centers (LANs) and at distributed sites (WANs). This is true and effective openness of enterprise wide networks that increases the speed of the deployments of new services and applications. Through open APIs at each layer and deep access to network resources through programmability, Cisco ONE Enterprise Networks Architecture creates the mutual awareness of networks and applications. This mutual awareness helps enterprises overcome the WAN challenges.

What's next:

In the next few blogs I'll cover additional aspects of SDN and Cisco ONE Architecture.

• Cisco ONE Architecture and ONE Enterprise Networks Architecture
• Details around the control layer for ONE Enterprise Networks
• Elaborate on Use-Cases in Branch and Campus networks

Thanks for reading and please comment on any and all aspects. I look forward to your comments. Stay tuned for the next blog post.