# Remote Wake-Up

- About Remote Wake-up

- Physical Installation Issues

- BIOS Settings

- Operating System Settings

## About Remote Wake-up

The ability to remotely wake computers is an important development in computer management. This feature has evolved over the last few years from a simple remote power-on capability to a complex system interacting with a variety of device and operating system (OS) power states.
Wake on Magic Packet
In early implementations of Remote Wake-up, the computer could be started from a power-off state by sending a Magic Packet. A Magic Packet is an Ethernet packet that contains an adapter’s MAC address repeated 16 times in the data field. When an adapter receives a Magic Packet containing its own MAC address, it activates the computer’s power. This enables network administrators to perform off-hours maintenance at remote locations without sending a technician out.

This early implementation did not require an OS that was aware of remote wake-up. However, it did require a computer that was equipped with a standby power supply and had the necessary circuitry to allow the remote power control. These computers were typically equipped with a feature named APM (Advanced Power Management). APM provided BIOS-based power control.

ACPI
Newer computers feature ACPI (Advanced Configuration and Power Interface), which extends the APM concept to enable the OS to selectively control power. ACPI supports a variety of power states. Each state represents a different level of power, from fully powered up to completely powered down, with partial levels of power in each intermediate state. Power states include:

Power State | Description
S0 | On and fully operational
S1 | System is in low power mode (sleep mode). The CPU clock is stopped, but RAM is powered on and being refreshed.
S2 | Similar to S1, but power is removed from the CPU.
S3 | Suspend to RAM (standby mode). Most components are shutdown. RAM remains operational.
S4 | Suspend to disk (hibernate mode). The memory contents are swapped to the disk drive and then reloaded into RAM when the system is awakened.
S5 | Power off

Some newer ACPI aware operating systems, such as Microsoft Windows* 98, Windows Me, Windows 2000 and Windows XP*, do not support remote wake-up from a powered off state (S5). These operating systems do support remote wake-up from intermediate states like standby and hibernate mode (S3 and S4).

Remote wake-up can be initiated by a variety of user selectable packet types and is not limited to the Magic Packet format. For more information about supported packet types, see the operating system settings section.

## Physical Installation Issues

Wake on LAN* (WOL) cable
For computers with a PCI 2.1 compliant bus
A Wake on LAN (WOL) cable is required on all remote wake-up capable adapters when used in older wake on LAN capable computers. These computers are generally equipped with a PCI 2.1 complaint bus and the BIOS is typically designed for APM compliant power management.

| NOTE: Remote Wake-Up from power-off (S5) is not supported on the following adapters in computers using the PCI 2.1 bus. To use Remote Wake-Up on any of the adapters listed below, the computer must have a PCI 2.2 compliant bus. Intel PRO/100+ PCI adapter (PILA8460BN) PRO/100 M Desktop adapter (PILA8460F) PRO/1000 T Desktop adapter (PWLA8390T) PRO/1000 XT Server adapter (PWLA8490XT)

For computers with a PCI 2.2 compliant bus
The Wake on LAN cable is not usually required for computers equipped with a PCI 2.2 compliant bus, as the wake up signal is routed through the PCI bus. This is done through the PCI connector pin defined as PME (Power Management Event).

Many of the newer ACPI computers also have a connector for the 3-pin Wake on LAN cable for backwards compatibility with older WOL capable adapters. In this type of computer, the WOL cable will still be needed for older 82558-based Intel® PRO/100+ Management adapter model numbers PILA8900 and PILA8461.

Slot
Some motherboards will only support remote wake-up (or remote wake-up from S5 state) in a particular slot. For example, the Intel® Desktop Board D815EPEA2 will only support remote wake-up from a powered off (S5) state if the adapter is plugged into PCI slot 2. It will, however, support remote wake-up from standby from any slot. See the documentation that came with your system or motherboard for details on remote wake-up support.
Power
Early versions of the Intel PRO/100+ Management adapter are +5 volt only. These models must have the 3-pin cable attached for the remote wake-up function to work. These adapters can be identified by the fact that they are equipped with 3 LEDs on the adapter bracket, whereas the PCI 2.2 compliant PRO/100 models have 2 LEDs on the adapter bracket. The older, +5 volt model adapters are not compliant to the PCI 2.2 specification and will not fit in a 3-volt only PCI slot due to the slot being keyed differently.

Newer Intel PRO adapters are 3.3 volt, but will work in a 5-volt slot also. They are keyed to fit either type of slot.

If your computer requires the 3-pin cable, then the +5 volt standby power supply must be capable of supplying at least 0.2 amps at +5 volts for each Intel PRO adapter installed (.6 amps for each of the older PCI 2.1 compliant management adapters). This value is usually listed on the power supply label as +5SB, +5VSB or +5AUX.

If your remote wake-up enabled computer is compliant to PCI specification 2.2, then it does not require the 3-pin cable for remote wake-up. In these computers, the 3.3 volt standby supply must be capable of supplying at least 0.2 amps for each Intel PRO adapter installed. You may need to contact your computer manufacturer to verify the standby current rating. Turning off the remote wake up capability on the adapter using the IBAUTIL utility reduces the power draw to around 50 milliamps (.05 amps) per adapter.

## BIOS Settings

There are various settings in the computer BIOS that may need to be configured before remote wake-up will work.

Many ACPI computers can be configured to work in APM mode. Check your BIOS settings to determine which mode you are operating in.

In both APM and ACPI computers, you may find settings for Wake on LAN* under the Power Control area and titled “Wake on LAN” and/or “Wake on PME”. Wake on LAN setting refers to wake up events received through the 3-pin header cable. Wake on PME refers to wake up events received through the PCI bus. To enable remote wake-up, you should enable the setting that corresponds to your adapter connection (e.g. set Wake on LAN to “enable” if you are using the WOL cable).

In ACPI computers operating in ACPI mode, if you are using an ACPI aware OS (such as Windows 2000), and wish to be able to power up the system from a power off state, look for an ACPI specific setting such as “Wake on LAN from S5” and enable it.

## Operating System Settings

Microsoft Windows Products
Microsoft Windows NT* and Windows 95 are not ACPI capable. Some settings will not be available in these operating systems. See also the “Other Operating Systems” section below.

Microsoft Windows 98, Windows Me, Windows 2000 and Windows XP* are ACPI capable. These operating systems do not support wake from S5 state, only from standby. When shutting down the system, they will shutdown ACPI devices including the Intel PRO adapters. This will disarm the adapters remote wake up capability. However, in some ACPI capable computers, the BIOS may have a setting that allows you to override the OS and wake from an S5 state anyway. If there is no support for wake from S5 state in your BIOS settings, then you will be limited to wake from standby when using these operating systems in ACPI computers.

In the Intel® PROSet advanced settings for some adapters, there is a setting titled Enable PME. To explicitly allow wake up with a Magic Packet from shutdown under APM power management mode, set this to Enable. See Intel PROSet help for more details.

In ACPI capable versions of Windows, the Intel PROSet advanced settings will also include a setting titled Wake on Settings. This controls the type of packets that will wake up the system from standby. Click the Help button in Intel PROSet for a complete explanation.

In ACPI computers running ACPI aware operating systems (such as Windows 2000), make sure the wake on standby option is enabled. To enable wake on standby, open the Device Manager and then navigate to the adapter properties tab Power Management. The setting “Allow this device to bring the computer out of standby” should be checked.

Other Operating Systems
In operating systems that do not support remote wake-up technology, you can still use the Magic Packet method of remotely powering up a computer. When the computer is first powered on, the Intel® Boot Agent configuration utility can be invoked by entering CTRL-S when the Boot Agent prompt appears on the screen. The configuration program has a parameter setting titled Legacy OS Wakeup Support. If this setting is enabled, the Boot Agent will pre-condition the adapter to respond to a Magic Packet wake up event. This allows remote wake-up in operating systems that do not support it. In early versions of the PRO/100+ Management adapter, this setting will not appear, and is not needed.

| NOTE: The Legacy OS Wakeup Support feature was not available in early versions of the Intel® Boot Agent. To update your Boot Agent to the latest version, download 100PBOOT.EXE from support.intel.com and follow the included instructions.

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