[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

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

570.0. "simple bridge query" by SUBURB::THOMPSONT (Tony Thompson UK Merchandising Tech Support) Thu May 14 1992 09:41

    My customer wants to bridge two LAN's 20 km apart, can he simply use
    two DECbridge 518's connected with single mode fiber, or does he need
    to use a concentrator ?
    Thanks in advance.
    Tony
    
T.RTitleUserPersonal
Name
DateLines
570.1It works, butLEVERS::S_JACOBSLive Free and ProsperThu May 14 1992 12:1021
    We have done this in the lab, and it works.  An S-port to S-port
    connection is legal, however I believe it is not recommended.  Maybe
    some other noter can supply the reasoning.  An alternative would be to
    connect two 528's in a DAS ring, but it would require two fiber-pairs
    instead of one.  You could also use a concentrator with a single-mode
    port card.   In that case the concentrator would sit next to one of the
    bridges, and you could use the cheaper multi-mode cable to connect the
    two.  
    
    
     DB510	  DC500					DB518
                w/ SM port card
     _____        _____                                 _____
    |     |      |     |                               |     |
    |     |      |     |                               |     |
    |__S__|      |_M_M_|           <=40km              |_S___|
        \_________/   \_________________________________/
          multi-             single-mode
          mode
    
    	
570.2S to S is OKQUIVER::PARISEAULuc PariseauThu May 14 1992 18:089
	I don't know of any reason why S to S (or S to A   or   S to B)
	would not be recommended.  It is perfectly legal and works fine.

	Luc

	ps.  Well, OK, in this case S to A or S to B if you had a DAS
	bridge would be fine.  If you do this on a trunk ring you would
	wrap the ring.  Still legal but not recommended.
570.3KONING::KONINGPaul Koning, A-13683Mon May 18 1992 13:506
Right.  S to S is perfectly valid and is very definitely worth recommending
in a number of places.  One thing you do need to keep in mind: it is exclusively
a two-station connection.  If you want to add a third node, you have to
introduce a concentrator at that time.

	paul