3270 controller simulation

Grant Taylor cctalk at gtaylor.tnetconsulting.net
Mon Nov 18 10:22:00 CST 2019

On 11/18/19 2:56 AM, Dave Wade via cctalk wrote:
> Whilst not what you are looking for some one has been working on 
> supporting CISCO SDLC encapsulation in Hercules.

Are they working on Cisco's SDLC line protocol and / or physical 
(serial) interface?

> So this allows real 3270's to connect to Hercules from a 3174 with only 
> SDLC ports by going via a CISCO router with an SDLC port.

So something like this:

[3270]---(coax)---[3174]===(SDLC)===??? ... ???---[Hercules]

What is the physical / logical connection to Hercules and the machine 
it's running on?

Or is this more like this:


In that the Cisco translates from the physical SDLC circuit to Ethernet 
and maybe does a protocol conversion to send things into Hercules across 
standard Ethernet?  Meaning that the Cisco becomes a fancy remote SDLC 
interface that Hercules communicates with?

I've been pontificating DLSw coming out of OS/390 running in Hercules / 
on my P/390-E to a Cisco and leveraging DLSw support to connect SNA 
(802.2 SNAP) to clients downstream.

This seems similar but is integrating an SDLC link to a 3174.

> I wonder if you could do the reverse. So go TN5250 into a Cisco and then 
> emerge as SDLC....

Hum.  I thought the TN5250 (and TN3270) was the 5250 (3270) protocol 
over TelNet.  As such, I don't think a 5250 (3270) terminal can speak 
the TN5250 (TN3720) protocol at all.  Instead, they need some sort of 
physical device that they can connect to that will gateway from 
<whatever> physical w/ 5250 (3270) protocol to any IP network with 
TN5250 (TN3270).

So, do any Cisco devices have twinax (?) interfaces for 5250 (or coax 
for 3270)?

I know that older & larger Cisco gear has the Channel Interface 
Processor that can attach to Bus & Tag channels from a mainframe and 
convert from TN3270 (I presume TN5250) to the physical B&T interface and 
necessary protocols there over for the mainframe.  But that's decidedly 
going the opposite direction.

Perhaps ~> hopefully I'm just ignorant of other solutions from Cisco, or 
anyone else, that will do what is desired.  I believe the *Remote* 3174 
(et al.) is one of these devices from IBM.  IBM's "Enterprise Extender" 
comes to mind too.  But I don't know what sort of down stream equipment 
that connects to.

Grant. . . .
unix || die

More information about the cctech mailing list