Cause value 101

Last Updated : Oct 15, 2014 |
[0x65/0xE5]

Message not compatible with call state/ Protocol threshold exceeded (NI-2: National ISDN 2)

Cause

Cause value 101 indicates that the equipment that sent this cause value receives a message that the equipment recognize, and procedures in the protocol specification indicate that it is not permissible to receive the message while in call state.

This cause value has local significance only. The ISDN network between the user and the equipment generating the cause value sends:

  • A no-cause indication through the network

  • A more generic cause value through the network

Cause value 101 (NI-2) can also mean that an established call or an establishing call is cleared because the threshold for multiple signaling protocol errors occurred during an active call is exceeded.

Proposed Solution

Procedure

  1. Check if the protocols at each end of the interface match, for example, both sides are AT&T Custom or both sides are NI-2. If the ends of the interface are using different protocols, then the protocols are used with different call state machines.
  2. Check the Communication Manager diagnostic information for the message type identifier that is in violation of the protocol. See Cause value 97, 98, and 101 diagnostic information.
  3. Call state problems are reported with STATUS messages. The equipment sending the cause value uses the CALL STATE IE of the STATUS message to indicate the call state. To determine the call state of the remote end, process the message sequence of the call with the SDL flow charts of the user side or network side with the appropriate protocol (TR41449/41459, TR1268, A211 etc.). If the call state at the remote end of the interface does not agree with the call state reported in the STATUS message and both sides are already using the same protocol, then the problem is with the implementation of the state machine on either side.

    There have been problems with the state machine implementations of some of the CO switches for different protocols, and the state machine problems in the CO switches are most likely not going to be corrected. Communication Manager has not revealed any problems with its state machine implementations for the different protocols.

    Change Communication Manager administration to alter the message sequence of the call scenario that causes the error. For example:

    1. change the transferring message on the DS1 form from PROGRESS to ALERTING
    2. change the wait steps in vectors to be i-silent so that they do not generate extra PROGRESS messages in the calling message sequence.