def update(self, ip_address=values.unset, friendly_name=values.unset,
               cidr_prefix_length=values.unset):
        """
        Update the IpAddressInstance

        :param unicode ip_address: An IP address in dotted decimal notation from which you want to accept traffic. Any SIP requests from this IP address will be allowed by Twilio. IPv4 only supported today.
        :param unicode friendly_name: A human readable descriptive text for this resource, up to 64 characters long.
        :param unicode cidr_prefix_length: An integer representing the length of the CIDR prefix to use with this IP address when accepting traffic. By default the entire IP address is used.

        :returns: Updated IpAddressInstance
        :rtype: twilio.rest.api.v2010.account.sip.ip_access_control_list.ip_address.IpAddressInstance
        """
        data = values.of({
            'IpAddress': ip_address,
            'FriendlyName': friendly_name,
            'CidrPrefixLength': cidr_prefix_length,
        })

        payload = self._version.update(
            'POST',
            self._uri,
            data=data,
        )

        return IpAddressInstance(
            self._version,
            payload,
            account_sid=self._solution['account_sid'],
            ip_access_control_list_sid=self._solution['ip_access_control_list_sid'],
            sid=self._solution['sid'],
        )