Hi Victor,
can you access INET service from cell server? On srv-sauvegarde you can try running:
telnet srv-testmgrange.grange-home.local 5555
If it's accessible you should get some baner like:
##########
HP Data Protector A.08.10: INET, internal build 207, built on Tuesday, August 25
, 2015, 9:06 PM
Connection to host lost.
##########
If it cannot connect make sure it there is no firewall blocking port 5555 communication between both hosts