given appropriate configuration and hardware, including remote wake-up across the Internet. In order for Wake-on-LAN to work, parts of the network interface need to stay on. This consumes a small amount of standby power, much less than normal operating power. The link speed is usually reduced to the lowest possible speed to not waste power (e.g. a Gigabit Ethernet NIC maintains only a 10 Mbit/s link). Disabling wake-on-LAN when not needed can very slightly reduce power consumption on computers that are switched off but still plugged into a power socket. The power drain becomes a consideration on battery powered devices such as laptops as this can deplete the battery even when the device is completely shut down. Magic packet The magic packet is a frame that is most often sent as a broadcast and that contains anywhere within its payload 6 bytes of all 255 (FF FF FF FF FF FF in hexadecimal), followed by sixteen repetitions of the target computer's 48-bit MAC address, for a total of 102 bytes. Since the magic packet is only scanned for the string above, and not actually parsed by a full protocol stack, it could be sent as payload of any network- and transport-layer protocol, although it is typically sent as a UDP datagram to port 0 (reserved port number), 7 (Echo Protocol) or 9 (Discard Protocol), or directly over Ethernet as EtherType 0x0842. A connection-oriented transport-layer protocol like TCP is less suited for this task as it requires establishing an active connection before sending user data. A standard magic packet has the following basic limitations: Requires destination computer MAC address (also may require a SecureOn password) Does not provide a delivery confirmation May not work outside of the local network Requires hardware support of Wake-on-LAN on destination computer Most 802.11 wireless interfaces do not maintain a link in low power states and cannot receive a magic packet The Wake-on-LAN implementation is designed to be very simple and to be quickly processed by the circuitry present on the network interface card with minimal power requirement. Because Wake-on-LAN operates below the IP protocol layer, IP addresses and DNS names are meaningless and so the MAC address is required. Subnet directed broadcasts A principal limitation of standard broadcast wake-on-LAN is that broadcast packets are generally not routed. This prevents the technique being used in larger networks or over the Internet. Subnet directed broadcasts (SDB) may