Complete VOS3000 SIP registration failed troubleshooting guide. Fix SIP error codes 401, 403, 408, 500, 503. Resolve wrong credentials, IP authorization, firewall, NAT, and SIP ALG issues.
VOS3000 SIP Authentication: Ultimate 401 vs 407 Easy Configuration Guide
VOS3000 SIP authentication 401 Unauthorized vs 407 Proxy Authentication Required. Configure digest authentication challenge mode SS_AUTHCHALLENGEMODE in system parameters.