Whereas your explanation offers further information (it was
an in-joke at the time to state that the derivation came from
the Plessey company, rather than from the Greco prefix, "Plesio"
meaning "nearly" as you say (also used in, "Plesiosaur", nearly a
lizard)), it does not give the lie to what I said, despite your
childish desperation to claim that it does.

There was a single master oscillator AIUI, but when service
finally came into exchanges via different links, it would result
in many phases of the frame dependant upon the route
by which signals had transited through the network, each link
being subject to frame slip, as you state.

The links were configured such that one end was the master
clock, and as such gave rise to a single master oscillator at
some point in the network. My memory may be in error on this
matter, but I am only human, I have never claimed omniscience
and it is 8 or 9 years since I worked on such system. No doubt
this will pass you by, and we can expect your usual childish broadcast
(CB) sneering at some minor error. How is it ever possible to
hold a technical discussion with you when you exhibit such a
personality defect, OM?

Why do you have to turn every technical discussion into
a ****ing contest? Are you that desperate to save the face that
you have undoubtedly lost by being a proponent of the
M3/CB Fool's Licence? You would certainly seem to be one
of the fools for whom the licence was intended.

Brian Reay wrote in message
...
"Airy R. Bean" wrote in message
...
ISTR that the Plesiochronous Digital Hierarchy of BT ran
via a single master oscillator.
Plesiochronous refers to a system with signals having a common data rate
(within defined limits) which are sychronised to different clocks.
Sometimes
referred tp as 'nearly synchronised'.
ie no 'master clock', with or without a remontoire ;-).
In a plesiochronous switched data system, the signals may be synchronised
at a given instant permitting switching withourt loss of frames but, when
the signals drift apart, the switches must compensate by a process known
as
'frame slip'- not required in a system synchronised to a master
oscillator.
I've no doubt you will respond with 'rubbish' etc. but I invite the others
on the NG to look up the term and decide who is correct.