Description: Number of Incorrect Messages detected on this interface. The Incorrect Messages Counter reflects any sort of incorrect information in a message. This includes:

- RELEASE, RELEASE COMPLETE, ADD PARTY REJECT, and STATUS messages transmitted, that contain any of the Cause values listed below.

- Ignored messages. These messages are dropped because the message was so damaged that it could not be further processed. A list of dropped messages is compiled below:

1. Message with invalid protocol discriminator

2. Message with errors in the call reference I.E. - Bits 5-8 of the first octet not equal to '0000' - Bits 1-4 of the first octet indicating a length other than 3 octets - RELEASE COMPLETE message received with a call reference that does not relate to a call active or in progress - SETUP message received with call reference flag incorrectly set to 1 - SETUP message received with a call reference for a call that is already active or in progress.

3. Message too short

The following cause values are monitored by this counter (Note: These cause values apply to both UNI3.0 and UNI3.1 unless otherwise stated):

Cause Value Meaning

10 VPCI/VCI unacceptable (UNI3.0 only) 36 VPCI/VCI assignment failure (UNI3.1 only) 81 invalid call reference value 82 identified channel does not exist 89 invalid endpoint reference 96 mandatory information element is missing 97 message type non-existent or not implemented 99 information element non-existent or not implemented

100 invalid information element contents 101 message not compatible with call state 104 incorrect message length 111 protocol error, unspecified

NOTE: For this counter, RELEASE COMPLETE messages that are a reply to a previous RELEASE message and contain the same cause value, are redundant (for counting purposes) and should not be counted.