Scaling up SDNs using TTPs (Table Type Patterns)

Software defined networking (SDN) solutions have been in the labs for a while, primarily to explore functionality and understand what possible benefit they could bring to current infrastructure and operations. Over the past couple years, SDN has emerged as a strong alternative for IT operations in the areas of WAN, data center and the overlay solutions. The primary benefit realized, besides open networking, is the ability to accelerate service deployments. SDN solutions using OpenFlow tackled complex problems including dynamic provisioning, interconnection and fault management. While the functionality of SDN evolved and matured, the scale of SDNs was still tied to ternary content-addressable memory (TCAM). OpenFlow by design was implemented in the TCAM.

A brief on Ternary Content Addressable Memory (TCAM) 

TCAMs are special memory devices that enable most of today’s intelligent networks. They enable match on a masked bit value rather than a binary match. This greatly enhances the usability of TCAM for network applications. There are many articles one can find on the Internet to get more details on TCAMs, but primarily they were responsible for the ideation of SDN. The possibilities in creating a policy-based forwarding model with a wild-card match introduced a multitude of network applications Continue reading

Adding a Full API to PicOS

Pica8′s PicOS is a Linux network OS based on Debian. This makes it easy for our customers to integrate their own tools or applications within PicOS. We are compatible with all the leading DevOps tools, such as Puppet, Chef, and Salt; and of course, we support OpenFlow.

But what if you would like to have an application on the switch itself to manipulate its data path? This is beyond the standard DevOps model and is not aligned with the traditional OpenFlow model, which uses a centralized controller.

Typically the requirement for such an application would be:
– A switch using traditional L2/L3, as well as an API to override those L2/L3 forwarding decisions.
– The API could be called on the switch itself while the application is running on the switch (that requirement would forbid a centralized OpenFlow controller).

For this use case, most network equipment vendors have an SDK (Software Development Kit) to program native applications running directly on the switch. A good example would be the Arista EOSSdk.

One big issue with those SDKs is that they are “sticky.” Once you develop your application, it only runs on the SDK provided by your vendor, Continue reading