With a pragmatic SDN definition in mind, such that “SDN functionally enables the network to be accessed by operators programmatically, allowing for automated management and orchestration techniques; application of configuration policy across multiple routers, switches, and servers; and the decoupling of the application that performs these operations from the network device’s operating system.”, we’ve been executing on all of these requirements. Our IETF deliverables are: the YANG modeling language, protocols such as NETCONF or RESTCONF, encodings such as XML and JSON, and some YANG modules.
Just after IETF 100 in Singapore in November, let’s analyze the current state of affairs in the YANG Data Models world. Note also the previous “YANG Data Models in the Industry: Current State of Affairs” from a year and half ago.
Let me start with a reflection. How do we know we’ve been fighting this uphill battle long enough and that it’s all downhill from here? Is it when we have published a core set of YANG models? When the technology is implemented by vendors? When the technology is deployed by operators? When other Standard Development Organizations/consortia/open-source projects embrace this technology? Probably most (or even all) of the above.
Now, an anecdote from this last IETF meeting. I was in a bar, connecting with IETF friends when, at some point in time, the discussion centered around YANG. In the past I would have lead the discussion, trying to convince and influence the crowd, but this time it was not necessary. I was quietly and happily sipping my beer while, Alia (an IETF routing Area Director), debated the importance of YANG. I enjoyed that moment so much and I remember observing that it is a success when someone else does your job. When someone else makes your speech. Then you know you can safely pass the baton. Now, downhill does not mean that there are no more issues to resolve, so let’s review the YANG models state of affairs.
1. The Network Management Datastore Architecture (NMDA) Impact
We keep specifying YANG modules at the IETF. See the graphical evolution here and all the published YANG data modules here. Why does it take so long, you may ask? Well, the world of standardization is never fast enough as quality and consensus come at a price. However, in this particular case, the main reason we aren’t fast enough is that we’re busy finalizing the “Network Management Datastore Architecture“, a new way to design YANG modules. To help grasp the concepts of this architecture we can look at pieces of the draft: