[j-nsp] questions regarding submarine cables

[Martin T]

This isn't directly related with Juniper, but hopefully not totally
off-topic as well :) At least here might be some industry insiders,
who have some experience with submarine cables.

1) According to engineer in this video: http://vimeo.com/29975179
..modern submarine cables are often built as self-healing rings. For
example "FLAG Atlantic (FA-1)" between USA and Europe seen here:
http://www.cablemap.info/ is a good example. How does such
self-healing ring works? Am I correct, that in case both cables are
healthy, only one of two is utilized with traffic? Who provides
equipment for such setups(I guess Alcate-Lucent is one of the
vendors)? In addition, how long it will take such switch-over to
occur? Are we talking about couple of milliseconds or few seconds?


2) In case cable has multipoint landings(for example "GLO1", which has
15 landings in west coast of Africa and Europe) then submarine
branching units should be in use. How this branching works? Are some
waves(CWDM) inside the cables switched towards the landing and other
continue via submarine cable? Because as I understand, on a wave
level, we are still talking about point to point connections(?). In
addition, are those branching units under the water or are they on
small islands, oil platforms etc if possible?


regards,
martin