o buffer unavailable errors Number of times that the Physical layer reported that no buffer was available to hold a message. This counter is not supported in all implementations. o crc errors received Number of frames received that had a bad CRC. o creation time Time at which this entity was created. o times pdu receive overrun Number of times a Physical line indicated an overrun condition to the Data Link layer. This counter is not supported in all implementations. o times pdu transmit failed Number of times that an attempt to send a frame failed. o up transitions Number of times that the entity's status attribute state has changed from off to on.