Conference netcad::hub_mgnt

3176.0. "Decrepeater 900FP connected to 90FA problem" by COPCLU::JENS () Thu Jan 18 1996 07:10

	Hi out there !



	We have some problems with a Decrepeater 900FP. 


	The configuration is as follows:



          Base
	Dechub 900
	Decrepeater 900FP--six--pairs--of-fibre--------------
	Decswitch   900EF                                    |
	Decrepeater 90T+ ---NT-server                        |
                                                             |
                                                             |
                                                             |   no.1
                                                             |  Dechub 900
							     Decrepeater 90FA
                                                             Decrepeater900TM
                                                             .
                                                             .
							     .
							     .
							     .
							     5 identical as
							     no.1 Dechub 900, 
							     1 on each floor 
							     in the building



	All floors in the building is connected to Decrepeater 900FP via a 
	decrepeater 90FA. The 5th. floor is running ok. All the other floors
	have problems and sees frame check errors, and PC's loosing conection
	to NT-server which is conected to the base HUB. On the HUB on the 5th
	floor there is no frame check errros. In the basehub there is no frame 
	check errors on the thinwire segment.
	No configuration is made on the Decrepeater 900FP, it is just plugged
	into the backplane in the base hub. We swapped the Decrepeater 900FP
	with no luck. We tried to disconnect all the floors to see if a
        specific floor was introducing errors without luck. We installed a 
	Decbridge 90FL in the Base hub and tried all the floors separately
	and they were all running ok when connected to a Decbridge 90FL. 

	Versions: Hubwatch 4.04 and Decrepeater 900FP firmware 1.2. 

	Any idea of what could be the problem ? It seems that there is pro-
	blems with the fiber-ports on a Decrepeater 900FP. Is the fiber-ports
	more sensitive on Decrepeater 900FP than on Decbridge 90FL ?



	Best regards 
	and thanks in advance 
	for any input 

	Jens Bondo, MCS-Copenhagen 

	Hi again !

        
	Here is some updates: 

	We inserted a Decrepeater 90FL in the base hub and moved  the 
	problem-floors to that device, and they don't see the problems 
	on thes floors anymore. 

	So we are still back to the Decrepeater 900FP. 



	Regards Jens 
	
	




                                                     

    I would try separating the 900FP ports into groups, and serving them
    from separate backplane ethernets, (served by the Switch 900EF over the
    backplane).
    
    I have the same configuration as you describe.  I have a switch 900EF
    and a repeater 900FP, in the downstairs computer room, and I have six
    remote DEChub900's, linked by DECrepeater 90FA, and I have no problems
    with frame errors, or CRC, or timing.  But I do have some Bridge90FL in
    the places where I have more than one hub per 900FP port group.
    
    You may be seeing a "too-many-repeaters" symptom, depending on the
    configs of your remote hubs.  By installing a bridge, you remove the
    symptom, which tells me that you need to study the 5-4-3 rule and look
    for violations, or media's that are too long.
    
    
    JR
    

	Hi again 

	Well we separated the Decrepeater 900fp into six groups and
	bridged them, and everything was then ok. Thank you all for 
	the help.

	Regards Jens