Intel® Remote Wake Technology Q&A

How does Intel® Remote Wake Technology (Intel® RWT) work?
What is an authorized service and client application?
What control do I have when setting up Intel® RWT on my PC?
Why does Intel RWT use a persistent connection for wakeup?
What is a sleep state?
What is a visually off active state and why is it used for Intel RWT?
Does Intel RWT also work in the hibernate mode?
If my PC is awaked by Intel RWT while I am gone, will it go back to sleep?
How is Intel RWT different than Wake on LAN?
How does Intel RWT download content from my PC?

1. How does Intel® Remote Wake Technology (Intel® RWT) work?

Intel Remote Wake Technology (Intel RWT) establishes and maintains a persistent connection to an authorized service on the Internet while your PC is in the sleep state. A special wakeup message over this connection from the authorized service to the PC causes Intel RWT to wake the PC up from the sleep state to a "visually off" active state and an authorized client application running in the host OS is notified about the wakeup. The application may then communicate directly with the service to handle the intended usage.

2. What is an authorized service and client application?

Intel digitally signs a vendor's application authorizing it to wake up the home PC when it receives a wake up message from a remote client (notebook or mobile device) with enabled service.

3. What control do I have when setting up Intel® RWT on my PC?

A user must enable each specific client application during the application's installation process to have Intel RWT enabled to wake up the PC. A user may also turn Intel RWT off for all client applications or for a specific client application.

4. Why does Intel® RWT use a persistent connection to service for wakeup?

This approach enables Intel RWT to deal with two issues in a home network environment. Typically, there's a router with a firewall between the user's home network and the Internet. To establish a connection from the Internet to a specific PC on the home network, requires the firewall and port forwarding to be configured for such connections. Generally, router firewalls are setup by default to allow connections to originate from a PC within the home network to a location on the Internet. Therefore, Intel RWT does not require special configuration to work within this kind of environment. Only the service that is the target for a persistent connection established by Intel RWT can send a wakeup message to the PC. This approach helps address both ease of use and security concerns.

5. What is a sleep state?

Sleep state is a lower power state for your PC that consumes significantly less power than the active state where users run and actively use applications in a host OS like Microsoft Vista*. For example, in a sleep state your system powers down hard drives and your monitor idled. Intel RWT continues to function while in the sleep state so that your PC can be awakened for any authorized client applications installed on your system which you have given permission to use Intel RWT.

6. What is a "visually off" active state and why is it used for Intel® RWT?

The active state is when your PC is fully powered up and you are able to run and use applications. "Visually off" is a special mode where your system is in the active state but your monitor is idled and the audio is disabled. Intel RWT awakens the PC from the sleep state to the "visually off" active state to minimize the disturbance that might be created in your home environment. Note that support for this "visually off" mode is dependent on the PC manufacturer.

7. Does Intel® RWT also work in the hibernate mode?

No, it works only for sleep mode so that faster transitions to the active state can occur. This is an important consideration for certain client applications such as VoIP where the user that initiated a call to your PC is expecting a timely response.

8. If my PC is awakened by Intel® RWT while I am gone, will it go back to sleep?

The "visually off" active state is set up to transition back to sleep when the authorized client application that received a wake up has completed its task. Either the client application itself can request to put the PC back to sleep immediately after completing its task, or else your normal power management settings will cause the PC to return to the sleep state. The latter option typically only takes minutes to happen.

9. How is Intel® RWT different than Wake on LAN?

Wake on LAN works by broadcasting the MAC address for the Network Interface Card (NIC) of the target device to wake up. Thus, each device that wants to wake your PC must be aware of and obtain this MAC address prior to using it. If the NIC on your PC has been configured to recognize this special packet, it will cause your PC to wake to the active state. This approach only works within a LAN subnet (your home network is typically set up as a LAN subnet) and is not routable over the Internet. There is also a User Datagram Protocol (UDP) form of Wake on LAN in which the MAC address is embedded in a UDP packet. This form of Wake on LAN can be routed over the Internet. In order for it to wake a specific PC in your home network, you must use the port that you configured with your router. In addition, your router must not issue an Address Resolution Protocol (ARP) request upon receiving the UDP packet since the target PC may be asleep and unable to respond, causing the UDP request to fail. Some routers rely upon their ARP cache and can be properly set up to work for this UDP Wake on LAN approach. Intel RWT bypasses all the limitations and issues described above, and it generally works with all routers without any complicated setup required by users.

10. How does content to my PC with Intel® RWT get downloaded from the Internet?

Intel RWT is a general wakeup mechanism for authorized services and client applications. The intended usage, such as downloading a weekly TV video, is handled by the service and client application.