[apps-discuss] tn3270

["Lyndon Nerenberg (VE6BBM/VE7TFX)" <[e-mail]>]

> Well, AFAIK, 3270 emulation is still in some limited use in commercial
> legacy mixed-platform environments, but I've never heard of practical
> usage of the 'tn3270' URI scheme in that context -- all such business
> applications are likely to operate based on tightly controlled local
> configuration of the access points and not driven by some kind of
> browser software operating on 'tn3270' URIs.

That's an awfully presumptive generalization to make about how other
people's businesses operate.  That aside, "must be accessible to the
global Internet" isn't a criteria for (or against) standardization (or
registration).  Standards can also apply inside walled gardens.

> There's a single RFC (RFC 3049) that contains a few embedded examples
> of 'tn3270' URIs, but it remains rather vague and does not give a
> reference for the definition of such scheme either.

I strongly suspect that's because the community of users for this scheme
are painfully aware of what the service represents, and therefore didn't
see a need to write it up.  It wouldn't take much effort to document it
in an RFC.

> So I'm also in support of declaring that provisional URI scheme
> Historic.

What is gained by doing this?  tn3270 is a very distinct service from
the NVT-ASCII terminal presumed by telnet:, even though both are
served over the TELNET protocol.  And the TN3270 service is far from
dead (e.g.  there are more than a few AS/400 systems connected to the
Internet).

Someone mentioned the tn3270 scheme made no sense being typed into a
browser.  URIs are used in *many* places other than browsers.  (On the
terminal I'm typing this on, right-clicking on any string prefixed
with 'tn3270://' will launch a tn3270 terminal emulator connection to
the specified host.)  While there's no formal specification for the
tn3270 scheme, it's pretty obvious what to do with the URI if you're
handed one in a context where you can establish the connection.

So let me turn this around and ask: what harm is actively being caused
by the tn3270 scheme that requires us to kick it to the curb?

--lyndon