The postwar TA43 field phone has two wires and two flashlight batteries. There is a push to talk switch on the handset, and no data capability by itself.
https://radionerds.com/index.php/TA-43~PT
I do know there was a switchboard that had patch cords for sending calls from scattered stations to one point, and directing the calls where needed.
The C42 radio had a handset that fed with WD1 phone wire to a junction box on the top tray. The remote had a thumb operated magneto on the handset which rattled a clacker in the junction box, and whoever was on radio watch could speak to the remote. I don't know if it had batteries or used the C42's power.