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Underlaying the SD-WAN Gives IT New Moves

So, as network IT manager you have has just been invited to join the DevOps team to spearhead the company’s push into new global markets – congratulations! As you head off to the first meeting, two thoughts cross your mind:

  • Can you provision the WAN connections as fast as the developers can rollout the new app and Marketing can generate product demand, and
  • Can you bring continuous cost reductions to the table?

Well, NaaS (Network as a Service) is a step in that direction, but you also need a tool to real-time negotiate changing WAN pricing and delivery conditions. An SD-WAN (Software-Defined Wide Area Network) with underlay management promises to take you there.

Network-as-a-Service Based on Underlay Management

SD-WAN virtualization and management requires control of both the IP layer and optical layer of service provider networks. Deployment and operationalization of Layer 0 (Dense Wave Division Multiplexing – DWDM) and Layer 1 (Optical Transport Network – OTN) – often referred to as the “underlay”, combines the virtual world and the physical world of optical networks. For software-defined control of the WAN to succeed, the underlay transport structure must be designed in a way that allows most if not all of its attributes to be controlled via software, but the physical reality is that the underlay resides on a line card, which requires data center space and manual installation as network demand expands rapidly.

The SD-WAN addresses multiple WAN pain points simultaneously

Constantly-rising demand, as well as pay-as-you-go pricing in the NaaS business, puts a strain on service providers’ ability to meet customers’ DevOps demand at the same time as optimizing traffic levels on their network. This has led to the broad adoption of systems that now integrate DWDM and OTN switching into a single system. When combined with an intelligent control plane technology and robust APIs, vendors can deliver complete abstraction and software control of all transport attributes to an SDN controller.

Facilitating Traffic Demands

In order to ensure smoother provisioning in the service providers’ physical data centers, switch vendors are moving to install high capacity e.g. 1 Tb/s on a single card with 10 x 100 Gb/s channels. Each individual 100 Gb/s channel can then be activated and licensed to the service provider separately. The unused channels are already lit, tuned, and locked but waiting to be software-activated to carry additional traffic. This approach reduces the need for manual interventions and bottleneck risks associated with sudden increases in traffic demand.

With the rapid increase in both east-west and north-south traffic demand, service providers must react to expanding customers’ bandwidth requirements in near real-time. Provisioning that previously took 4-6 weeks to negotiate and two weeks to install at the customer site can today be done in minutes. This presupposes software activation of network capacity initiated by end users, and such a service was recently announced by Pacnet.

As a managed data connectivity provider, Pacnet is extremely sensitive to shifts in customers’ data transmission, It wants a new service provider-customer relationship and dialog through more WAN transparency. To help accomplish this, Pacnet has upgraded its Pacnet Enabled Network (PEN) to offer an SDN-enabled NaaS platform across 46,000 km of fiber connecting 15 DCs in 11 Asia-Pac countries. The PEN service deploys network virtualization of the Optical Layer using Infinera’s Open Transport Switch r1.0. This Open Transport Switch API uses the underlay (rather than the more tradition overlay approach) to allow any SDN controller to communicate with all network nodes (not just the end points) to obtain higher network efficiency, end-to-end visibility and path control, in order to meet customer SLAs most efficiently.

The Customer Perspective

Customers get a self-service portal where they can specify end points, bandwidth, duration, latency etc. The PEN DC replication app monitors spot pricing on available transport links, determines optimal time to initiate connection and offers the customer the most competitive pricing while simultaneously optimizing Pacnet’s resource utilization. On their side, the customers can negotiate pricing and conditions with their service provider – much like buying an airline ticket where time of day and routes affect prices significantly. Similarly, by exploring volume transmission options in low traffic periods or via more round about routes with associated higher latencies, data managers can cut down on traffic expenses where it does not affect business needs.

The take-away                                                                

The SD-WAN addresses several WAN pain points simultaneously: faster provisioning of network resources while simultaneously alleviating traffic congestion; providing end-users with more visibility into network performance and management; and reducing the need for manual intervention which is costly and may create network traffic bottlenecks. By using managed service provider SD-WAN options in their NaaS guises, IT departments can gain experience with fast network provisioning, and work in co-operation with their DevOps teams who typically need iterative test-and-deploy activities with fluctuating network demands.

About the author
Bernt Ostergaard