User's Manual

Troubleshooting
Back-to-back Configuration on the Same Host
Chapter 8 215
Back-to-back Configuration on the Same Host
NOTE This section does not apply to 712 Series workstations.
Systems with multiple X.25 interfaces can use back-to-back
configurations to perform diagnostics. If you suspect that a switch might
be the source of your connection problem, you can set up a back-to-back
configuration to test the circuit without the PAD switch.
To set up a back-to-back connection on a single host, you connect one
card to another card on the same host through a modem eliminator, as
shown below. The modem eliminator provides the necessary clocking for
the DCE. The most common modem eliminators are RS-232 and V.35.
Figure 8-6
In order for two cards (on the same host) to communicate, one card must
be configured as the DTE and the other card as DCE.
To set up a card as DCE, use the x25init command and enter DCE_80,
DCE_84 or DCE_88 (according to the standard you are using) in the
networktype parameter.
You must also make sure that the two cards are using compatible level 2
parameters.
Card 1 Card 2
HOST
Modem
Eliminator