UTT-901 User Manual21Agent is common.Expire Time Configurate the register expire time of private server.STUN EffectTimeInterval time for STUN’s detection on NAT type, theunit is minute.Enable SIP Stun Configure enable/disable SIP STUN.Enable PrivateRegisterConfigure permit/deny private server register.Enable PrivateOutbound ProxyConfigure enable/disable private outbound proxy.After the aforesaid configuration has been done, click apply to make themgo into effect.4.5.3 Value- added service configurationOn this page, user can set value-added services such as hot-line, callforwarding, call transfer (CT), call-waiting service, three way call,blacklist, out-limit list and so on.