Industry Trends in Networking

The long journey to factorize Network Management problems by decoupling policy from configuration has let to a variety of outgrowths of controllers to mange networks.

During this journey we faced different approaches on Network Programmability Models. We started with vendor specific API or simple CLI/SNMP, Classic OpenFlow based SDN, Hybrid SDN based on “ships in the night” or “integrated mode”, Network Virtualization with Virtual Overlays to finally arrive at “policy intent” or also described as “Managing Networks through abstractions”.

The Promise of OF/SDN had been
Decoupling Policy from Configuration

So what actually is SDN:

  • Is the physical separation of control and data plane?

  • Is packet forwarding on general x86 compute?

  • Is whitebox routing and switching?

  • Is running our network in a agile DEV-OPS model?

  • Is managing the network through abstractions!

You can’t just buy SDN.
It’s an architecture which you have to embrace and life

From Cloud over SDN towards Abstractions to a final fully distributed system

Today’s DC Architectural Battle

System administration is over – we should stop doing it

Web Approach (MSDC)

  • IT infrastructure core of its business
  • Warehouse Datacenter
  • Scale-Out Architecture
  • ~100.000 of physical servers
  • Single Application Optimization
  • Many smaller services
  • Application Designed for Failure
  • Automate everything possible
  • It’s all about being super-cheap commodity systems; costs must grow in a “sub-linear” fashion
  • Open Source
  • Backbone Bandwidth Calendaring
  • TDM style provisioning with custom TCP stack
  • L3 Topology

Enterprise Approach (EPDC)

  • IT infrastructure is an expense
  • “Discovery” Datacenter
  • Scale-Up Architecture
  • ~10.000 physical servers
  • Hundreds to Thousands of Applications
  • Application trust boundaries
  • HA failover model
  • Transactional
  • Application specific Infrastructure
  • Commercial Of The Shelf
  • L2 Topology

Driven by todays applications and digitization efforts the datacenter and in particular the MSDC’s are leading the agenda and there is an ongoing DC Architectural Battle based on misassumptions on requirements.

Main limitation factor for Enterprise to compete with MSDC offerings is typically not the network itself, this are old isolated and not mashed applications. While apps gets re-written to address the digitization needs with modern software development tools the expectation is that the network will be able to be programmed likewise by current development tools which leads towards a DevOps model.

As new application development no longer happens in isolation and the production system is becoming the development platform the logical next question coming up is why can’t I simply use my datacenter tools like PUPPET, CHEF and ANSIBLE likewise for Enterprise networks?

However, main takeaway from that ongoing battle is: “System administration is over – we should stop doing it” and what could be achieved by “Efficiency through abstraction and automation” based on Device to Admin Ratio comparisons over the last years.

Efficiency through abstraction and automation

Device to Admin Ratio



Traditional IT: 50:1

Amazon: 200:1

Google: 10000:1

Traditional IT 50:1

Amazon 10000:1

Google: 30000:1

Conclusions for Enterprise Controllers

From this discussion there are some main design points derived when it comes to requirements for controllers for Enterprise networks.


  • Reduce Network Complexity
  • Brownfield Support – No Software / Hardware upgrade required
  • Low Risk adoption of SDN
  • Enterprise Scale for real life production network use
  • Product with minimal to no programming requirement
  • Auto-Translation of high level business intent into network control function


  • Abstraction and Automation of Manual Network Operations
  • Advanced Visualization (HTML5/Java code with object oriented interface)
  • Start with small set of solvable problems (QoS, ACL management , Zero Touch Deployment and IWAN as key applications with identifiable metrics (OPEX savings , ROI)
  • Elastic Services Infrastructure ensures scaling as adoption grows
  • Advanced analytics for real time network visibility and faster response time

Don’t make it simpler by making it more complex!

Where we are with SDN 2016, five years later

The SDN Hype Cycle is over now and customers are at “Trough of Disillusionment” while still searching for an solution of the original problem.