[May 29 18:17:31] NOTICE[3343][C-00000004] chan_sip.c: Failed to authenticate device "06xxxxxxxx" <sip:06xxxxxxxx@freephonie.net;user=phone>;tag=1 05 20-TE-005c7476-239405c57
as tu bien tout rempli comme indiqué ici :

https://wiki.xivo.fr/index.php/XiVO_...rconnexion_SIP