Conference netcad::hub_mgnt

2191.0. "Can DEChub 90 handle the pace" by RDGENG::GREID (Hook.....in....mouth!) Thu Apr 13 1995 04:46

    
    One of the Engineering groups here at REO whose office connections are
    served by a DEChub 90 with 5 DECrepeater 90Cs are due to a change round
    of their main clusters. I intend to via thinwire, wire the following
    CPUs into a couple of the ports on the Hub so that I can manage the
    connections remotely instead of wiring these nodes directly off of taps
    on their main segment.
    
    Is the fact that the nodes are heavily used clusters, both of which  
    are Alpha clusters serving lots of disks (also one is main ALL-IN-1 
    development cluster) and their are a couple of heavily used Infoservers
    in this, going to slow down the performance of the repeater/Hub once
    I wire them in ?
    
    The CPUs are :-
    
    			DECsystem 4610
      			4000-105a	      Cluster 1
    
    			DECsystem 4710
    			4000-600	      Cluster 2
    
    			2 * Infoservers
    
    
    Traditionally I would wire these off their own taps, maybe the
    infoservers I would add to the Hub as the VXTs that boot off of them
    are wired into the Hub anyway.
    
    Any thoughts on this ?
    
    
    	Thanks,
    
    	Giles.
    	REO Engineering Networks.

    Hmmm,
    Well the 90Cs are Ethernet repeaters, which operate at the physical
    layer. You can think of the DEChub 90 with these repeaters the same as
    you would one long piece of ThinWire, except there's more delay across
    the repeaters than across the wire. 
    
    Assuming you aren't violating any cable lengths, you should get the
    same performance from the DEChub 90 that you get from a ThinWire
    segment. So, it's really an issue of how much traffic you have relative
    to Ethernet's 10Mbps bandwidth.
    

    Thanks for the reply, I went ahead with the connections and all is
    ok as I monitored the Hub with a Probe afterwards. I was only really
    worried that the Alphas would saturate things.
    
    Giles.