Remote Control, Keep-Alive, Pause Frames

3CR990-FX-97 NIC Features

Remote Control

The 3CR990-FX-97 NIC can also receive commands via Remote Control and Management Protocol (RMCP). This feature is also speciﬁed in the ASF speciﬁcation and lets network administrators troubleshoot and resolve system issues across the network. Commands include:

■Power on

■Power off

■Reboot

■Reboot from an alternative device (for example: MBA, CD-ROM, and so forth)

Both monitoring alerts and sending commands are available in the system console through the 3Com Remote System Alert Manager. This management plug-in is available for HP OpenView Network Node Manager, Microsoft Systems Management Server, and Intel LANDesk Client Manager.

Keep-Alive

The 3CR990-FX-97 NIC can also transmit a workgroup keep-alive packet periodically while the computer is in a sleep state. This packet prevents the computer workstation address from being aged-out of switch router tables.

Hot Plug NIC Installation

If your computer supports PCI hot plug speciﬁcations, you can add a new 3Com NIC or remove and replace a 3Com NIC without turning off power to the computer. Hot plug NIC installation allows you to expand connections without taking the computer out of service. It makes troubleshooting faster and easier because you do not need to wait for the computer to reboot.

For instructions on performing a hot plug NIC installation, refer to your computer documentation.

Flow Control Features

The 3CR990-FX-97 NIC uses ﬂow control technology to throttle the incoming data packet stream and prevent the loss of packets. IEEE 803.2x ﬂow control prevents the input buffers of a device from overﬂowing. By using pause frames to communicate buffer status between linked transmitting and receiving devices (transmitters and receivers). A receiver sends a pause frame to tell a transmitter to stop the transmission of data frames for a speciﬁed period, allowing the receiver’s input port buffers to empty before receiving new packets.

Pause Frames

When a transmitter receives pause frames, it suspends transmission for the speciﬁed period. When the receiver’s input buffers can store packets again, it can either send another pause frame to tell the transmitter to resume transmission, or wait for transmission to resume at the end of the speciﬁed period.

With asymmetric ﬂow control, only one of two linked devices can receive pause frames. With symmetric ﬂow control, both linked devices can send and receive pause frames.