Conference netcad::hub_mgnt

1333.0. "Repeater counts with 90FS/900FP ?" by BRIEIS::BARKER_E (test dummy) Mon Aug 22 1994 12:32

    Hi,
    
    	I'm working on a configuration where a combination of 900FP and
    90FS repeaters would appear to be ideal, I just want to check a couple
    of points :-
    
    	The config I am looking at is :-
    
    
    
    Workgroup 1 --- 90FS ===Primary link ====== 900FP (in DEChub 900 with
                      ||                         | |   bridge 900MX &
                      ||                         | |   Concentrator 900MX) 
                      ||                         | |   
                      ||                         | |FDDI Ring
                      ||                         | |
                      ||                         | |
                      ||===secondary link ===== 900FP (in second DEChub
                                                       900 with same
    						       config. as above)
    
    
    According to the 900FP manual the above looks fine, the plan would be
    to have about half a dozen similar workgroups connecting into the
    900FP's in a similar manner to workgroup 1 shown above. My concern is
    with the repeater count if systems in workgroup 1 need to communicate
    with systems in workgroup x, in theory the path would be 90FS - 900FP -
    90FS, a repeater hop count of 3. Is this still illegal ? If so, can I
    get around this by possibly using DECbridge 900's in place of 900FP's ?
    If so is the 900MP bridge the right option and does it support Fibre
    connections, and am I right in thinking that I would be losing full
    fault detection capability and having to settle for partial fault
    detection ?
    
    	Thanks for your help, hope I've been clear enough !
    
    		Euan  
    
    
    There will be a number of workgroups which
    
    
                   

    Should've read the ethernet Notes file first, sorry, there's numerous
    dicussions there. Just for info, the config. I described is OK, the
    repeater rule is actually :-
    
    5 segments maximum
    4 repeaters maximum
    3 co-ax segments maximum (out of 5 above, others can be Fibre or UTP)
    
    I guess the old 2 repeater limit came from the fact that we would have
    then had three coax segments in the old days, hitting the 3 coax
    segment limit, not the repeater limit.
    
    So, my config is OK, great !
    
    Euan

    Just to flay this old horse again (I can never seem to get it buried):
    
    There never was a 2 repeater limit. The confusion came from referring
    to the two ends of a remote repeater link (two repeaters connected by a
    length of fiber optic cable) as a "repeater set" or "2 half-repeaters".
    The 5-4-3 rule was simply a means of clarifying what had always been
    the configuration rule from the beginning.
    
    Even now, though, some of the product documentation continues to refer
    to a two repeater limit....just another windmill to tilt at.
    
    	/Harry