drives, redundant power supplies, etc., will help to maximize availability. Additionally, a device which can switch the machine off and on again, controlled perhaps by a remote signal, can force a reboot which will clear problems due to misbehaving software. For a machine not in constant use, energy can be conserved by putting the machine into low-power RAM standby after a short timeout period. If a connection delay of a minute or two is acceptable, the machine can timeout into hibernation, powered off with its state saved to disk. Wake on Internet The originator of the wakeup signal (magic packet) does not have to be on the same local area network (LAN) as the computer being woken. It can be sent from anywhere using: A virtual private network (VPN)which makes the originator appear to be a member of the LAN. The Internet with local broadcastingsome routers permit a packet received from the Internet to be broadcast to the entire LAN; the default TCP or UDP ports preconfigured to relay WoL requests are usually ports 7 (Echo Protocol), 9 (Discard Protocol), or both. This proxy setting must be enabled in the router, and port forwarding rules may need to be configured in its embedded firewall in order to accept magic packets coming from the internet side to these restricted port numbers, and to allow rebroadcasting them on the local network (normally to the same ports and the same TCP or UDP protocol). Such routers may also be configurable to use different port numbers for this proxying service. The Internet without local broadcastingif (as often) the firewall or router at the destination does not permit packets received from the Internet to be broadcast to the local network, Wake-on-Internet may still be achieved by sending the magic packet to any specified port of the destination's Internet address, having previously set the firewall or router to forward packets arriving at that port to the local IP address of the computer being woken. The router may require reservation of the local IP address of the computer being woken in order to forward packets to it when it is not live. See also Alert on LAN Alert Standard Format Desktop and mobile Architecture for System Hardware RTC Alarm Wake-on-RingTelephone line ring event Conventional PCI pinoutPower Management Event (PME#) signal Wired for Management References Computer-related introductions in 1997 Networking standards BIOS Unified Extensible Firmware Interface Remote control