Pat
Two points:
1. Well, that I didn't know! When it comes to heating yourselves up or
cooling yourselves down, homage is still paid to the old country[1]. Lord
North will be ever so slightly pleased.[2]
2. To the extent that NCP is still pumping SNA blood around in, say, the CCL
replacement for the 3745 - and a few 3745s yet I expect, NCP is still
processing BTUs. I had to check up on this somewhat intermediate
architectural unit and - shame! - it took a Microsoft (HIS) site and a Cisco
(SNASw) site to be sure.[3] I (re)discovered that a BTU is the assemblage of
the TH and BIU - typically the RH and RU - before it is checked against the
MAXDATA specification and segmented into PIUs. Of course, if the BTU is not
allowed to be segmented, a BTU is the same as a PIU.
I hope I got that right. I used to teach this stuff! My somewhat ancient SNA
Concepts presentation doesn't even bother with the BTU but goes straight
from BIU to PIU. However, strictly, once you add the TH to the BIU (with the
segmenting bits and data count not yet determined) you have a BTU - always
have, always will ...
Chris Mason
[1] BTU = British Thermal Unit -
http://en.wikipedia.org/wiki/British_thermal_unit
[2] http://en.wikipedia.org/wiki/Frederick_North,_Lord_North
[3] From the Cisco site: "BTU - (basic transmission unit) In SNA, the unit
of data and control information passed between path control components. A
BTU can consist of one or more path information units." SNA Formats mentions
BTU from time to time, in XID fields for example, but nowhere spells out
what it means!
----- Original Message -----
From: "Patrick O'Keefe" <[EMAIL PROTECTED]>
Newsgroups: bit.listserv.ibm-main
To: <[email protected]>
Sent: Wednesday, September 19, 2007 9:07 PM
Subject: Re: Humor a little OT
On Tue, 18 Sep 2007 22:09:12 -0500, Ed Gould
<[EMAIL PROTECTED]> wrote:
...
I killed my career by replying, "Actually, sir, it's cooling the
room. The
computer is over there."
...
It was a standing joke at my job that the datacenter management
couldn't tell the air conditioners from the CPUs. Then I found out
that early NCP processed BTUs[1] and decided that IBM couldn't
tell the difference either.
Pat O'Keefe
[!] Basic Transmission Units
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