🚀 go-pugleaf

In article <1992Aug4.145923.15557@relay.nswc.navy.mil>, snorthc@nswc.navy.mil (Stephen Northcutt) writes:
|>
|>I work for a fairly large campus.  The buildings are connected to
|>12' x 24' concrete shacks we call comsheds.  The comsheds terminate
|>2 1/2" multi tube duct which gets filled with various appropriate
|>media.  The duct goes from com shed to com shed.  To date the inter
|>com shed distance has not exceeded 1500'.  We are about to span
|>5 kilometers to reach an in-the-boonies section of the campus.
|>
|>We think we want to span this distance using single mode fiber.  To
|>that end we have ordered a six fiber bundle.  Now the question is
|>what to stick on the ends of the fiber :-)
|>
|>One engineering approach would be to implement FDDI over singlemode.
|>We have FDDI capable routers, what do we need to use FDDI over
|>singlemode?
|>
|>Thank you!
|>-- 
|>===================================================================
|>   ** my dream: voice, video, data, 3 services, 1 network **
|>===================================================================
|>
|>Stephen Northcutt (snorthc@relay.nswc.navy.mil)     Networks Program Manager

Sounds like a good plan.  What you need is a device that has a single
mode PMD.  Most convenient would be a router whose FDDI line card has 
such a PMD.  Failing that, you might connect the router to a concentrator
that has single mode ports (router to multimode port of the concentrator,
concentrator to single mode fiber across campus).

Least desirable is an outboard "converter" -- a device that simply accepts
an arbitrary multimode optical signal and produces a corresponding single
mode signal.  Such devices aren't explicitly supported by the FDDI
standard and have been known to cause problems in some cases.  (They  have
also been known to work in some cases...)

	paul