Thx for your answer, but i'm surprise that it doesn't work because it's an intel network card..
EDIT:
I used the 1.02b loader for DS3617XS, and the network car is working. But new problem when i try to install manually the pat 15284 https://global.download.synology.com/download/DSM/release/6.1.7/15284/DSM_DS3617xs_15284.pat
i have an error: Failled to format the disk.
So i have try differents versions and loader, 3615XS, pat 15284-1, -2, - 3, same for 3617xs, but still the same error message.
I have 4 disk inside the T20.