He Who Thought He Knew Something About DASD 367
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I could have used your story to make my PPOE staff a bit less grumpy...
in the reference about supporting a couple hundred IMS people moving from bldg.90-STL to a location about 10 miles away:
... a similar configuration was installed when the FE IMS service people in boulder were being relocated to a bldg. across the street (from the bldg. they had been in that housed the datacenter). Bascially HYPERChannel (channel extension) over T1 link ... but in this case it was using infrared modems on poles on the top of the respective bldgs (aka effectively providing channel extensive so that people would be using and experiencing local 3270 response ... as opposed to what they would get if they were to be subjected to remote 3270 operation).
there was concern that because of the weather in the boulder area, that it might adversely affect the signal quality. it turns out to not being as bad as people feared. in a white-out blizzard when nobody was able to make it into work ... we started seeing slight elevation in the bit-error rate.
this was one of our HSDT efforts
on so we had multiplexer on the T1 link with (firebird) bit-error testers running constantly on a 56kbit side-channel monitoring signal-transmission quality. i had written a program that ran on a pc ... and simulated a terminal to the serial port of the bit-error tester ... logging all the data and then reducing and plotting the information.
Happened last week. A RAID 1, first drive failed, replaced it, second drive failed 8 days later. Both failed drives from the same manufacturing batch...
for a little topic drift, there was a different problem that resulted in signal loss. turns out that the infrared modems have a fairly tight footprint and it didn't take much to get the modems out of alignment. It wasn't wind nor rain that was identified as causing the problem. It turns out that in the course of the day ... the sun unevenly heated the sides of the building ... causing first one side to expand-contract and then the other side. This asymmetrical expansion-contraction of sides of the building resulting in the poles (that the modems were mounted on) to lean enuf during the course of the day (to get out of alignment).
from some turbo pascal archive, long ago and far away (all of this was before snmp) ....
On my web site, I had proposed a computer design which started out as a...
{$V+,R+,B-,C-,U-} {note: the C- & U- aviods losing type-ahead} (* FIREBERD minimize ERROR entries in cases of prolonged high-error rate conditions. Calculate ERRORs-sec Make no more than one entry in ERROR per 15 minutes unless ERRORs-sec change by more than 50%. minimize ERROR entries for sync lost-sync acquired loops. ULTRAMUX recognize alarm messages define status flags for various alarm messages when sync. is lost, include fireberd information in screen COM2 asynch interrupt check for Asynch card interrupt ... if not asynch, restore status-regs and goto saved IRA (i.e. cascaded IRQ4 interrupt routines) *)
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