[j-nsp] Service Provider Shaping vs Policing

[James Jun]

On Wed, Apr 19, 2017 at 01:44:19PM -0400, Skyler Blumer wrote:
> Is this a single point of failure? For example if one 10GE NNI goes 
> down, are customer's backauled to this NNI down until they can be 
> manually moved over?

It is and it isn't, depends on how you evaluate the risks.

In our case, both IP POP and transport network meet in the same suite at the colo,
typically in their same cage or private room, so there is no third party access or
outside plant fiber involved on these interconnects.

As for optics failing or line card dying causing the NNI to go down -- same situation
can be said of any interface.  By that statue, every customer port connecting into our
network would be single point of failure, unless the customer opts for redundant ports.

For customers paying redundant ports, we haul them to two physically separate IP POPs
and would run BGP across both circuits.  So if NNI dies or the whole POP dies, other
side stays up.

For NNI's terminating to the same equipment, I don't see how LAG adds much practical
redundancy other than eery corner cases (like SFP dying bringing down a link member).
If anything, using LAG to aggregate subrate circuits IMO just increases complexity on 
queueing and policing operations.  We use LAG when we need to increase aggregate capacity
available to a link path, but not for reasons of redundancy.  If I need redundancy,
we build diverse.

James