🚀 go-pugleaf

As I understand the current situation, unless a non-ATT carrier has
equal access (or a special "answering supervision" feature package,
the details of which I won't go into here) in the TERMINATING central
office for a call, they are unable to positively identify supervision status.

The letter from MCI says they don't start timing after a certain
number of rings or interval of time.  But they didn't mention the
OTHER technique some non-ATT carriers use--trying to watch the path
to detect when non-recurring audio (e.g. speech) begins.  As anyone
who has tried to do this will tell you, it is tricky at best.  And
of course you'll be fooled by intercept operators and recordings.

I'm not saying that this is what MCI is using--but given their 
statement about a "highly sophisticated" means of detecting when
a call is answered, it sounds like they might be using this for
termination in non-supervision central offices.  After all, true answering
supervision status, when properly handled, isn't "highly sophisticated"
at all--but it works.

--Lauren--