Re: CenturyLink RCA?

[Dave Temkin <dave () temk in>]

On Mon, Dec 31, 2018 at 11:33 AM Naslund, Steve <SNaslund () medline com>
wrote:

> They shouldn’t need OOB to operate existing lambdas just to configure new
> ones.  One possibility is that the management interface also handles master
> timing which would be a really bad idea but possible (should be redundant
> and it should be able to free run for a reasonable amount of time).  The
> main issue exposed is that obviously the management interface is critical
> and is not redundant enough.  That is if we believe the OOB explanation in
> the first place (which by the way is obviously not OOB since it wiped out
> the in band network when it failed).
>
>
>
> Steven Naslund
>
> Chicago IL

A theory, and only a theory, is that they decided to, in order to
troubleshoot a much smaller problem (OOB/etc.), deploy an optical
configuration change that, when faced with inaccessibility to multiple
nodes, ended up causing a significant inconsistency in their optical
network, wreaking havoc on all sorts of other systems. With the OOB network
already in chaos, card reseats were required to stabilize things on that
network and then they could rebuild the optical network from a fully
reachable state.

Again, only a theory.

-Dave



> > This seems entirely plausible given that DWDM amplifiers and lasers
> being a complex analog system, they need OOB to align.
>
> > --
>
> > Eric