this.ua = new SIP.UA({

// User Configurable Options
uri:               this.options.ua.uri,
authorizationUser: this.options.ua.authorizationUser,
password:          this.options.ua.password,
displayName:       this.options.ua.displayName,
// Undocumented "Advanced" Options
userAgentString:   this.options.ua.userAgentString,
// Fixed Options
register:          true,
sessionDescriptionHandlerFactoryOptions: sessionDescriptionHandlerFactoryOptions,
transportOptions: {
  traceSip: this.options.ua.traceSip,
  wsServers: this.options.ua.wsServers
}