Conference netcad::hub_mgnt

2848.0. "6-port dual-attached concentrator capability?" by TOPTEN::LEONARD (Paid to play) Tue Oct 10 1995 08:06

I have perused this notesfile and the available sales literature, but am 
still unclear regarding configuration of a def1h and 
decconcentrator-mx... 

Could someone *PLEASE* confirm/negate :

	With the use of a DEF1H and a DECconcentrator-MX a six port 
concentrator can be created and dual attached to an FDDI ring...latest firmware
assumed...

The question really boils down to is the configuration of the 
DECconcentrator the same as the DECswitch 900 EE/EF - a port can either 
point in or out of the backplane, and pointing a port into the backplane 
gives you one less port for external connectivity?  Or, is there some 
other way to configure the 900MX that effectively enables you to 
configure and use the eight ports that one sees mentioned randomly in 
literature and the FDDI config guidelines?  My intentions are to create 
a dual attached concentrator with six available spurs - will this work 
with the combo of a DEF1H and DECconcentrator-MX?

Thanks !
/jane

    Jane,

    The DECconcentrator 900xx are different than the DECswitch 900EF in
    regards to the FDDI ports. When you point the ports of the concentrator
    out the back, the corresponding front panel ports revert to M ports
    and are available for use.

    Using the DECconcentrator 900MX and DEF1H, configure it so that you have
    A and B ports out the back. All 6 front panel ports are available as M
    ports. Likewise, with the DECconcentrator 900TH all 14 front panel ports
    are available with A,B out the back. So they are true 8 and 16 port
    concentrators. The switch only has 2 ports whether they are front or back.

    (In case you didn't see it) this is discussed in the paragraphs
    accompanying diagrams 2 - 5 in the  FDDI configuration guide in note
    #2340.

    -Mike

    Mike,
    Thanks for the quick reply!
    /jane