At position U5, U6, U19 and U20 the BAD cards will have part
number DS14C89. The "C" indicates a CMOS type chip. The cards
fail as detailed below. Cards manufactured after July 7th are
updated cards and should not have the "C" chips.
USR has denied the existence of the fix to several other customers
I am currently working with on these problems.
John Robarge
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Original message follows
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I recently audited a POP for a client in search of "Portmaster
Problems" and learned a few things that were fairly amazing.
The reported problems:
user dial-in sessions were hanging on for hours
ports were not resetting properly
ports hung in username state
The customer had already tried:
Reset port on portmaster - no effect
power cycle portmaster - problem cleared most of the time
User assumption:
Because I can power cycle the portmaster and clear it, the
problem is of course the portmaster and besides USR says it's
not their problem :)
My plan of attack and observations:
I took a breakout box to the POP and began doing "sho all"
to find the "bad ports". I found about 150 ports out of
about 1100 were "bad". To diagnose the problem I inserted
the breakout box and discovered that CD was high even though
no caller was attached to the modem! I removed the modem
from the front of the rack (the USR has separate modems that
slide into the front and serial interface cards called NICs
that slide in the back) and still got CD from the serial
interface card! On other ports I saw various other signals
high and in error. As I replaced the USR NIC cards with
spares, I found that about a third of the brand new spares
were also bad.
Resolution:
USR after weeks of denial admitted that it had a design flaw
in the NIC card that blew a chip if the portmaster was powered
on and the USR rack was powered off. If a POP loses power it's
essentially a race between the USR and the portmaster to see if
the USR NIC card will be fried. A redesign would be needed
and ALL NIC CARDS REPLACED to cure it.
Last status from customer:
The client reports that they have received "thousands" of NIC
cards and have begun the replacement process. The problems have
NOT resurfaced on replaced ports.
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-MZ
-- Livingston Enterprises - Chair, Department of Interstitial Affairs Phone: 800-458-9966 510-426-0770 FAX: 510-426-8951 megazone@livingston.com For support requests: support@livingston.com <http://www.livingston.com/> Snail mail: 4464 Willow Road, Pleasanton, CA 94588