Troubleshooting

Symptom

Two devices cannot ping each other over an ISDN PRI or BRI line.

Analysis

The following are typical ISDN call failure causes:

Solution

To resolve the problem:

  1. Execute the display isdn call-info command to verify the interface settings:

    1. If the command displays nothing, configure an ISDN interface. For more information about configuring BRI, CE1/PRI, and CT1/PRI interfaces, see Interface Configuration Guide.

    2. Verify the Q.921 state of the PRI or BRI interface:

      • If the PRI interface's link layer 1 is not in ISDN MULTIPLE_FRAME_ESTABLISHED state, Q.921 negotiation has failed. You must check Q.921 settings or the physical connection.

      • If any link layers of the BRI interface are not in TE1_ASSIGNED state, Q.921 negotiation has failed. You must check Q.921 settings or the physical connection.

      • If the Q.921 state is correct, verify the dialup configuration.

  2. Verify that the physical layer is active:

    1. Enable Q.921 debugging.

    2. If the system displays a "Failed to send" message, execute the shutdown and undo shutdown command to re-enable the interface.

  3. Verify that the dial-up configuration is correct.

  4. Verify that the ISDN cables are securely connected.

  5. If the problem persists, contact Hewlett Packard Enterprise Support.