Not quite actually Erno.
There’s a 10/100 Ethernet transceiver (PHY) built onto the S800 board itself, but the S800 also supports a GbE PHY (that “RGMII for 2nd Ethernet…” on the data-sheet) via an external 10/100/1000 Ethernet Transceiver within the dCS units.
I posted previously, w.r.t the loop port, and the specific transceiver chips used;
(By the way, you attached the older/original S800 data-sheet, not the specs of the current boards).