SipManager: setautoregisterandpolicy () --> SipService: openpolicysession () --> SipSessionGroupExt: opentoreceivecballs () opentoreceivenovel () --> AutoRegistrationProcess: start () --> first, perform the anti-registration (duration = 0) SipSessionGroup. sipSessionImpl: unregister () --> SipSessionGroup. sipSessionImpl: doCommandAsync () --> SipSessionGroup. sipSessionImpl: processCommand () --> SipSessionGroup. sipSessionImpl: process () --> SipSessionGroup. sipSessionImpl: readyForCall () --> SipHelper: sendRegister () --> AutoRegistrationProcess: onRegistrationDone () --> registration is completed, and then registration (duration = 3600) orautegistrationprocess: run () --> SipSessionGroup. sipSessionImpl: register () --> SipSessionGroup. sipSessionImpl: doCommandAsync () --> SipSessionGroup. sipSessionImpl: processCommand () --> SipSessionGroup. sipSessionImpl: process () --> SipSessionGroup. sipSessionImpl: readyForCall () --> SipHelper: sendRegister () --> AutoRegistrationProcess: onRegistrationDone () --> complete