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KVM over Wireless When Doing a Warm Reboot or Power Up

Wireless LAN (WLAN) connections to Intel AMT are normally made via the host operating system wireless driver when the host is active. Intel AMT can take control of the wireless LAN directly, but in this case the host will have no WLAN connectivity, so it is preferable to maintain the host link.

Intel AMT can manage this behavior with a link preference parameter associated with the Ethernet port settings for the WLAN. The preference can be either the host driver or the ME. The ME may also take control of the link, even when the host has preference, if, for example, the host is powered down or asleep or the driver is not functioning.

When a KVM session is set up over a wireless port, the connection is normally done using the host operating system driver, which forwards the connection to Intel AMT. If the IT operator wishes to initiate a restart of the host, the operator should command a change in link preference to the ME. The KVM link is handed over seamlessly to Intel AMT and is maintained across the restart operation. The IT operator can observe and control BIOS activities with no problem. However, when the host comes back up and the host wireless driver restarts, the KVM link will be lost. The following steps show how to manage this situation.

note-icon Note:

Starting with Release 8.1, when the link protection feature is enabled, it automatically protects WLAN connectivity.  This eliminates the need for manual link control of a KVM session over a wireless link.

 

1.  Before performing the restart, set the wireless port link preference to ME:
Invoke AMT_EthernetPortSettings.SetLinkPreference for the instance whose DeviceID is “Intel(r) AMT Ethernet Port 1”, setting LinkPreference to ME and Timeout to a long enough value to complete the necessary actions (for example, 300 seconds). The KVM session will transition to ME control and the host will lose its wireless network connection. See Set/Get Link Preference and Control for a description of this flow.

2.  Perform the restart command using remote control functionality. The KVM session will be maintained across the restart.

3.  During the restart, perform any necessary BIOS commands.

4.  When the operating system restarts, the KVM session will still be maintained (subject to the Timeout parameter), but the operating system will still have no wireless connectivity. To restore host connectivity, issue the AMT_EthernetPortSettings.SetLinkPreference request with HOST as the LinkPreference. This will cause the KVM session to be dropped.

5.  Reestablish the KVM session to be able to manage the host after its wireless connectivity is restored.

Note that this process will succeed with an operating system restart or an Intel AMT remote control reset or if the platform is put into a sleep state that is compatible with keeping Intel AMT active (for example, with this power package: Mobile: ON in S0; ME Wake in S3-S5/AC).

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