HP General IO Connectivity manual Back-to-back Configuration on the Same Host

NOTE

Figure 8-6

Troubleshooting

Back-to-back Configuration on the Same Host

Back-to-back Configuration on the Same Host

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.

HOST

Card 1

Card 2

Modem

Eliminator

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.

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