[TriLUG] The thin line...

[Rick DeNatale]

On 10/6/06, Ryan Leathers <rleathers at americanri.com> wrote:
> Got me thinking... fairly off topic
>
> I didn't read that Andrew was talking expressly about web servers.
> Maybe he was instead talking about mainframes as packet switches /
> routers.  Some of that went on in the early days, but it certainly
> doesn't work that way any longer.  I don't think it was ever even the
> norm.  In the mid 80's DARPANET was handing over networking
> responsibilities to the NSF.  To that point, they had been using front
> end processors to handle the network traffic chores rather than the
> mainframe proper.  It wasn't until the NSF got involved that more
> mainframes were added, and considerable growth occurred resulting in the
> need to hold sizable routing information and process packets at such a
> rate that the mainframe became interesting as a network infrastructure
> component.
>
> By the late 80's, appliance routers were already showing up.  The famous
> Cisco quote goes something like "People had a long history of buying
> things that plugged into the wall, made noises and got warm."
> So, the idea of an expensive mainframe as a network infrastructure
> component was already on the way out once the software to handle routing
> had been coupled with a cheap hardware platform.

If we're talking about traditional IBM mainframes, most network
traffic never went THROUGH them.

Even back in the days of SNA, it was the communications controllers
which handled the network traffic, only things destined for the
mainframe ever went there.

And not just network data, but IO in general. That's really what
distinguished mainframes. The CPUs weren't all that powerful, it was
the IO infrastructure. The I/O channels on IBM mainframes were really
specialized computers and could do pretty sophisticated data transfer
without involving the CPU once they got started.

What we are seeing these days is pretty much parallel, with LAN/SAN
distributed processing replacing the old IO channels.


-- 
Rick