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Conference netcad::hub_mgnt

Title:DEChub/HUBwatch/PROBEwatch CONFERENCE
Notice:Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7
Moderator:NETCAD::COLELLADT
Created:Wed Nov 13 1991
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:4455
Total number of notes:16761

2626.0. "Cabletron and Digital repeaters on the same FO LAN?" by HACMAN::HACK (Don Hack, Network Services) Thu Aug 10 1995 01:21

    Are there any known issues with mixing DECbrige 90FLs and DECrepeaters
    90FL's with Cabletron repeaters, FOTs, and bridges on the same network.
    
    The customer is getting poor performance (DECnet retransmits) from bad
    frames/CRC/fragments, etc. when they leave the local office copper LAN
    and venture out into the fiber optic backbone - which is primarily
    Cabletron MMAC-3's connected to a MMAC-8 .. almost all of them
    repeaters.  There are two bridged MMAC-3 and several DEChub90's with
    90FL repeaters or bridges.
    The 90FL's are at FirmWare rev 1.0 or 2.0.  I bet the Cabletron
    firmware is old too.  I am going to ask the client to upgrade firmware.
    
    In reading the notes files, there was mention of 10baseFL vs 10baseFB
    regarding Digital and Cabletron, respectively.
    Is this too an issue?
    
    Right now it looks like if a Cabletron FOT-F2 is infront on a Cabletron
    bridge, performance is bad.  If there is no FOT, performance is fine.
    I am working on the FOT/bridge issue, but wanted to make sure that
    there is also not a Digital/Cabletron interaction issue.
    
    Any comments appreciated.
    Thanks ... Don
T.RTitleUserPersonal
Name		DateLines
2626.110BaseFL versus 10BaseFBLEMAN::PAIVAHawkeye - Network Support @GEOThu Aug 10 1995 07:417
    Yes, 10BaseFL versus 10BaseFB is an issue. Digital products are only
    10BaseFL. If Cabletron's are 10BaseFB, then you should choose to use
    only one of the manufacturers' repeaters...
    
    Pedro PAIVA
    Network Support Team
2626.2How much of a problem?HACMAN::HACKDon Hack, Network ServicesThu Aug 10 1995 13:4213
    re: .1
    When you say 10BaseFL and 10BaseFB should not be connected together,
    what will be the results?
    - No traffic will get throught
    - some packets will be regularly trashed
    - works 95% of the time
    
    Also, *how* backward compatable is our 10Base-FL implementation to
    FOIRL standard?  The Cabletron boxes claim to meet IEEE 802.3 FOIRL
    specifications.  Is there a real difference between IEEE 802.3 FOIRL
    and just claiming FOIRL support?
    
    Thanks ... Don
2626.3don't connect FL to FBLEMAN::PAIVAHawkeye - Network Support @GEOFri Aug 11 1995 13:159
    I don't know what would be the result of connecting a 10BaseFL to a
    10BaseFB but these are definitely different standards.
    
    As far as I can remember, 10BaseFL is the standard that evolved from
    FOIRL...
    
    Cheers,
    
    Pedro
2626.4This is what I have been told......CGOOA::PITULEYAin't technology wonderful?Fri Aug 11 1995 15:249
    10baseFB is some kind of proprietary synchronous communications
    protocol that was developed for use in backbones.  Essentially, it
    allows distances longer than the 10baseFL spec due to the fact that it
    does wierd things with timing.  
    
    Brian Pituley
    NPC, Calgary
2626.5NETCAD::B_CRONINFri Aug 11 1995 15:406
    
    10Base-FL is a 2 km version of FOIRl. It interoperates with FOIRl, but
    can go the longer distance. If Cabletron says they meet FOIRL, that
    means they should interoprate with 10BASE-Fl, but not at distances
    longer than 1 km.
2626.6You probably need more bridges and routers.MSDOA::REEDJohn Reed @CBO = Network ServicesMon Aug 21 1995 04:2411
    A 10BaseFL transceiver or repeater or Star, cannot communicate with a
    10BaseFB device.   If you connect them to each other, NO TRAFFIC will
    pass.  I have a customer with this very config (built last month,
    thanks to a Sales Rep, who will remain nameless), and it does not work.
    
    Since you are getting traffic, you are following the 10BaseFL spec.  I
    think that the problem is repeater counts, and packet delay.   I would
    be that many late collisions are occuring.   Do a timing (model 1 and
    2) analysis on the worse case link, and see what you get.
    
    JR