Voice and data use different frequency bands for transmission over PSTN wire. Usually data is transmitted on higher frequencies than voice.
On ATX side the incoming signal is divided into high (data) and low (voice) frequency components via frequency splitter.
The cause section indicates that the number dialed is unassigned on unallocated. Are you able to dial in a different fashion? For example by adding or removing the country code?
1 < Cause (len= 4) [ Ext: 1 Coding: CCITT (ITU) standard (0) Spare: 0 Location: Public network serving the local user (2)
1 < Ext: 1 Cause: Unallocated (...