6.1.6.1.2. Non-Voice 
Fax connections are recorded in the call detail recording for internal
traffic under the "Fax" service and data connections are recorded under
the "Data" service.
The type of the service ("fax" or "data") is registered in the call
detail record.
Under the "data" service, no subdivision is done according to data
transmission speed or according to special data service type, such as
X.21 or synchronous/asynchronous.
Internal calls of the following device types are recorded for non-voice
calls:
- Euro-ISDN (S0 and S2)
- DCI and DCI-compatible devices
- Modem at an SLMA interface and on the a- and b-interfaces of an S0 terminal adapter (Euro-ISDN).