Neil Croft wrote in a message to Mike Bilow:
 MB> Most mainframe operations we deal with have SNA, "boa" channel cables,
 NC> Would they be the big blue (or grey) Bus and Tag cables?
 NC> I've dragged a few of them recently.
Yes, "boa" is a slang term for the bus and tag channel cables, usually blue.  
This is because their appearance in a large shop is similar to a number of 
snakes lying along the ground, and their effects can be similar if you don't 
keep careful watch where you are going.
 MB> or ESCON fiber.  If a mainframe operation has Ethernet, it is likely
 MB> that it was installed fairly recently and that it is UTP.
 NC> All our ICL's talk to the rest of the world via a 10base5
 NC> ring albeit we convert it at the taps to 10baseT.
You don't mean a "10Base-5 ring."  IEEE specifically uses 10Base-5 to mean 
Ethernet, not the wiring alone.  Maybe you mean IBM Twinax?
 NC> The IBM's currently just use Token ring via cat-3 or cat-5 from 
 NC> the channel connected controllers (3174s and 3274s). We're 
 NC> currently scoping a move over to Ethernet in our building due 
 NC> to the limitations of translational switches (ie. they don't 
 NC> translate) so 2 of the 3174s need to be converted to Ethernet. 
Trust me: don't do it.  IBM had people camped out in one shop here for almost 
two solid months trying to get a 3174 to speak Ethernet.  It finally worked, 
but it was to the point where the IBM people were informally told to just 
come in wearing jeans and T-shirts after a couple of weeks, since they were 
not going anywhere except the machine rooms.
 NC> All round, with a new ethernet switch, hubs, 3com cards (We use 
 NC> Transcend) and 2 Ethernet cards for the 3174s, we reckon on 
 NC> around 30k (UK) for the hardware. That excludes the ongoing 
 NC> wiring upgrade to cat-5 in the building.
Well, let me put it this way: when we had IBM service on the phone from North 
Carolina trying to fix this, there were so many people on the line that the 
bills were approaching US$1000 per hour.
 NC> Labour will be another matter. How long to change >350
 NC> machines to Ethernet? 
 NC> Loads of overtime.=o) 
Buy a router with both token ring and Ethernet capability, and purchase the 
proper software licenses for SNA.  You will be much happier if you don't have 
to plug Ethernet directly into the mainframe boxes.  It will save you piles 
of money and months of work.
 
-- Mike
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