Cause
The call cannot be completed because the ISDN network is functioning incorrectly. The condition is not likely to last a long period of time. The call will complete if the user reattempts the call.
Cause value 41 also indicates:
The failure of channel negotiation at the terminating interface.
A data link layer malfunction has occurred locally or at the remote network interface.
The call is cleared as a result of one or more protocol errors at the remote network interface.
See also Cause value 63 and Cause value 79.