Each ring builder has two external trunk connections by which a ring builder may be connected to other token ring devices capable of supporting a backup path, e.g. another ring builder. Each external connection attaches to a dual ring cable. One of the rings is used to carry traffic in a fault free network. The other ring is used as a backup. If an error should be detected on the main ring then suitable stations can wrap the active path onto the backup. The ring builder is such a device. The fault recovery is handled at the ring in and ring out ports. Control of the external connections is via the Ring In Mode parameter. If the connection is in FAIL-SAFE mode this parameter reflects the automatically determined state of the connection. If the mode is NOT FAIL-SAFE this parameter will read the same as the mode parameter.