"This is because existing standards have either failed to (1) be
   massively adopted so far ...
or (2) address service provider and network
   operator requirements about configuration framework and procedures."

[WEG] I think this is incomplete as currently presented. I don't think it's a 
failing of the existing standards, and I think the challenge is much larger.

First, a quote I've always found appropriate for framing this discussion: "The 
first rule of any technology used in a business is that automation applied to 
an efficient operation will magnify the efficiency. The second is that 
automation applied to an inefficient operation will magnify the inefficiency." 
- Bill Gates

There are two different but related issues with automation of network 
provisioning and management:
1) a lack of will to invest in a real, continually improved and updated 
automation environment - it's sometimes cheaper to "throw headcount at a 
problem" than to make a long-term investment in automation, especially since 
the industry is littered with attempts to do automation that have ultimately 
failed, making the return on the investment somewhat questionable. It also 
requires a permanent staff of people to maintain and improve the system, rather 
than it being a once and done sort of investment. Some companies are good about 
this, because they have management that understands the productivity multiplier 
that proper automation can provide and are willing to invest in it, others are 
not, sometimes because they try to force a tool to automate their current 
process as-is rather than trying to streamline their process around the 
capabilities of the tool.
2) healthy mistrust by operators and management of the automation's level of 
intelligence and ability to make the "right" decision given all possible 
scenarios it might encounter. This could be restated as an inability to either 
characterize or pre-build business rules around all possible scenarios. It's 
unclear to me whether this is because the tools available are simply too crude 
to adequately represent the series of scenarios that your average human 
operator is capable of handling, or because the average SP has too much 
variability in its scenarios such that "if A occurs, do B" isn't realistic for 
all possible values of A. We may need to differentiate between simple business 
logic and complex when it comes to automation requirements, since it's much 
harder to solve the latter, but we can maybe make good progress on the former.

When it comes to network automation, the options today are usually either 
"build your own system mostly from scratch" or "buy a COTS package and then 
work to adapt it for your needs and integrate it into your internal systems". 
Both of these options can use standards-based protocols, but those could be 
thought of as the modular building blocks for a "some assembly required" 
implementation that is almost always bespoke. Even if you have good 
north/southbound APIs to work with, someone has to work on the glue to hold 
everything together. A good implementation requires a lot of work to document 
functional spec and business logic (or adapt existing process to better fit the 
limitations and capabilities of the tool), a lot of testing to ensure that 
things are working properly, and the ability to make changes easy enough that 
it isn't simpler/cheaper to bypass the automation and have someone do it 
manually when something changes. So in a way, the necessary modularity for 
flexibilit
 y and adaptability and the necessary predefinition to make implementation easy 
"out of the box" run counter to one another. The good news is, it's extensible, 
so you can adapt it for your needs. The bad news? It's extensible, so you 
likely MUST adapt it for you needs in order for it to be useful.


3.4/3.5 - there are more performance and scaling impacts than this - most 
notably, a poorly-implemented discovery mechanism will do things like attempt 
synchronization too frequently, or do it inefficiently by attempting to pull 
down a complete configuration and then do diffs on its stored data, rather than 
requesting  diffs directly and storing those updates, or waiting for a 
notification that something it cares about has been changed before going out to 
synchronize with that particular network element ONLY. It may also try to 
discover network elements by walking through IP ranges, which doesn't really 
work for IPv6. It's also pretty common for there to be a lack of coordination 
between different tools that need access to the same data, and rather than 
pulling the data once and then replicating it to all of the different tools 
that need it, each tool polls separately, leading to situations where a box 
collapses under the load of too-frequent and overly-aggressive SNMP pollin
 g, etc.
I remember problems in production with a certain VPN provisioning software 
where its timeout for pulling the complete configuration was too short, and on 
routers with large and complex VPN configurations the config sync step would 
fail because it took the router too long to uncompress and "display" the config 
to the TTY, especially if the base CPU load was too high.
There are a good number of scaling/performance considerations for VPNs 
specifically discussed in draft-gs-vpn-scaling that may help with this 
discussion.

I generally agree with the requirements, but it's possible that the above 
discussion will generate additional requirements, so I didn't spend a lot of 
time pondering them yet.

Thanks
Wes George

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