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Conference 7.286::fddi

Title:FDDI - The Next Generation
Moderator:NETCAD::STEFANI
Created:Thu Apr 27 1989
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2259
Total number of notes:8590

158.0. "FDDI connectors - help!" by VAXRIO::ROLF () Mon Oct 22 1990 16:36

    I have been asked to help configuring our first FDDI network. It
    is a small network, consisting of two Concentrators in a ring and
    some 9 bridges hanging off of them.
    
    Having never seen the equipment before and only only having access
    to the books, I got confused as to what fibers/connectors to use
    and I would like to kindly ask someone to confirm (or correct) my
    suspicions:
    
    1. To interconnect the two concentrators (they sit right next to
       eachother) I can use BN24B-03. That is port A to port B and vice-
       versa.
    
    2. To connect a concentrator to a DECbridge500 which sits right
       next to the concentrator I can use a BN24B-XX cable.
    
    3. If the bridge is more distant from the concentrator I will
       have to use a BN24D-XX cable at both boxes, connext those BN24D's
       to patch-panels and interconnect those patch-panels with some
       more fiber which has ST-connectors at both ends.
    
    4. There is no way I can connect a bridge to a concentrator by using
       a single, "self-made" cable, having ST connectors at both ends. In other
       words, the bridge and the concentrator ONLY accept those MIC
       connectors.
    
    Any help is very much appreciated.
    
    Thanks
    
    Rolf,
    NWSS Rio de Janeiro, Brazil
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158.1Sounds goodAKO569::JOYGet a life!Tue Oct 23 1990 12:009
    Rolf,
       I don't have the part numbers in front of me but the plan that you
    stated sounds right. The main thing to remember is to "key" the MIC
    connectors properly ("A" key goes into "B" key). Your last statement is
    correct, the bridge and concentrator only accept the MIC connectors so
    you really couldn't "build your own" cables.
    
    Debbie
    
158.2more on ST-to-STBAGELS::LEVYTue Oct 23 1990 13:447
    re: .0
    
    1,2,3 correct as stated.
    
    On 4: Note that the FSD MIC is only planned for ANSI-compliant optics.
    In particular, low-power optics will use ST-connectors. BN24E-xx is the
    DECconnect offering for ST-ST patch cables. 
158.3getting closer...VAXRIO::ROLFTue Oct 23 1990 15:0925
    Oh, I see....  BUT:
    
    1. Where does that DEFCN-LA/MPH number come from? The T & N Buyers
       Guide does not show this "MPH" number. What is the difference
       between the DEFCN-LA/MPH and a DEFCN-NA? (both ANSI compliant)
    
    2. Am I correct that there is no low-power optic board (or version)
       for the bridge, so I would still be forced to use a MIC connector
       at the bridge end, even though at the concentrator I could use
       ST connectors?
    
    3. One more: That "keying" of the connector is done in the field when
       installing the cable. Right or wrong?
    
    Sorry if I am asking for small details, but not having any hardware in
    the country, we want to be very sure to be ordering the correct
    and complete hardware necessary.
    
    Thanks for both answers!
    
    Rolf                
    
    
    
    
158.4More answersAKO569::JOYGet a life!Tue Oct 23 1990 16:0723
    Rolf,
     
    1. I think your confusion comes from not having seen the Sales Update
    article concerning the Low Power Optics card. It appears the part
    numbering scheme has changed some from when the T&N Buyers Guide came
    out. The DEFCN-LA/LF is the Low-Power Optics Port card. The
    DEFCN-LA/MPH is the ANSI Optics Port Card. The DEFCN-LA/LF have optics
    that have lower optical power budgets than ANSI optics 7 db vs 11 db.
    Using this loss bodget and the low power optics, the acievable
    interstation distance is 1 km. The low power optics are fully
    compatible with ANSI optics and can be mixed and matched with ANSI
    optics in a concentrator or in the ring.
    
    2. As of now, there is no low power optics board for the DECbridge 500.
    Most likely there will be one before too long. But you can plug the
    regular DECbridge into a low power optics board in the concentrator
    with no problem. 
    
    3. Yes, the keying is done in the field. Each MIC connector comes
    with an attached cap and in the cap are the keys.
    
    Debbie
    
158.5No low power for DECbridge 500BAGELS::LEVYFri Oct 26 1990 14:1711
    re:             <<< Note 158.4 by AKO569::JOY "Get a life!" >>>
       
   > 2. As of now, there is no low power optics board for the DECbridge 500.
   > Most likely there will be one before too long. 
    
    There are no plans for offering low-power-optics on the DECbridge 500.
    
    The difference in optics cost for a single FDDI port does not yield an
    appreciable price benefit to the customer.