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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

3304.0. "non DEC RJ45 logging high counters" by CSC32::D_HIGHLAND () Thu Feb 22 1996 18:16

    Has anyone seen high counts of LEM, LCT, connects completed, and ring
    inits on a 900MX UTP mod pmd port with third party cables?  Mainly the
    connector head itself.
    
    What we've found is a slight difference in connector length, but it
    appears to be making a real difference in the connection, or lack of
    in this case.  
    
    At this point it is only speculative, however, we've seen it one other
    time, as soon as the DEC cable was used, the above mentioned counters
    quieted.
    
    File access and copies are failing, the port LEDs go from Green to
    Amber...then back to green after a couple of minutes.  We've tried
    other ports, other MX's, other controllers, and OS (OpenVMS and WNT).
    
    We have tried other cables but all have been made outside DEC.
    
    Since the configuration is valid, and the versions are all current
    (except the MX is running V3.1.1 ...I think the latest there is
    V3.2.x).  We've asked the customer to try one of our cables. (big
    sale!)
    
    Has anyone seen similar symptoms with non-DEC cables?
    
    Dave Highland
    CSC/CS
T.RTitleUserPersonal
Name		DateLines
3304.1RE: El-cheapo cables ....NETCAD::BATTERSBYFri Feb 23 1996 09:009
    Dave you might want to try posting this question in the FDDI
    notes conference UPSAR::FDDI. For those who might see your post
    here, it might help if you can be specific about the vendors 
    who make the cables in question. That way our engineering folks
    responsible for our FDDI cables can get some of these and possibly
    analyze them. You may also want to include this additional info (vendors)
    in your post in the FDDI notes file too.
    
    Bob
3304.2do they have the correct cable?NETCAD::MELARAGNIFri Feb 23 1996 14:1515
    Are you sure that the non-DEC cables are actually Cat 5 behind-the-wall 
    cables? 
    
    There are two kinds of Cat 5 cable -- "behind-the-wall" and "patch cord". 
    "Behind-the-wall" cable is designed to meet the EIA/TIA-568 specs for 
    cable loss for lenghts up to 90m. Patch cord has a much higher loss and as 
    such is limited to 10m total length. If your customer is using patch
    cord of lengths greater than 10m, then this might be the problem.
    
    You can usually tell patch cord from the behind-the-wall cable by the
    flexible nature of the patch cord. The behind-the-wall cable is usually
    stiff.
    
    bill
3304.3It's patch cord and may exceed 10mCSC32::D_HIGHLANDFri Feb 23 1996 18:1514
    He is connected to his Alpha's PCI UTP controller (DEFPA) directly from
    the 900MX MOD PMD UTP port.  No "behind-the-wall."  This is the reason
    he went to the third party make.  Digital's solution (I don't have the
    part number) for this cable was only 3 meters.  He needed at least 6
    meters, however, it may actually be longer, I'll have to check.
    
    Our 3 meter cable appears to be for wall connections only.
    
    I will cross post this in FDDI as well.
    
    Thanks for the information.
    
    Dave