PURPOSE OF THE LINK
The ethernet connection between my laptop and the fast ethernet port of the Cisco 2911 will be used by the DLSW encapsulation function of the router to contact the 'other router' to carry the SDLC traffic between the serial port on the router, hooked to my IBM 3174 terminal controller, and a mainframe system.
The other router is really code built into the 3705 emulation function of Hercules which strips the SDLC from the link and processes it as if a serial line were configured between a real 3705 communications controller and the remote 3174. Thus the mainframe emulated by Hercules thinks it has a 3705 using a leased line to talk to the 3174.
IBM and Cisco developed the DLSW encapsulation as a way of transporting the serial traffic over a TCP/IP network instead of Telco leased lines. The 3174 on one side and the 3705 on the mainframe data center side both have serial port connectors, but instead of those being cabled to modems, they hook to serial interfaces on Cisco routers. The routers carry the serial traffic inside TCP/IP.
I hooked up an ethernet cable between the laptop and the router. I set up the fast ethernet port of the 2911 as 192.168.0.1 and configured my laptop's ethernet port as 192.168.0.2. I then booted up the router making use of a USB serial link for the console port of the router and the command processor of Windows on the laptop side.
I did some pings to see that the packets were sent both ways over the ethernet cable, then started a telnet client on windows and pointed it at the router address. This opened and I had the logon prompt that I could use to connect to the router's IOS environment. This ensure that I have a good link on this end.
Once the outdoor environment is healthy I will hook the serial port of the router to my 3174 and cable the ethernet to the laptop. After I boot the router and start Hercules, I am IML the 3174 controller. If all goes well, the serial link will be established between 3174 and 2911, then I can start DLSW and IPL the MVS 3.8J image under Hercules.