Allied Telesis AT-2973T User Manual
Chapter 1: Introducing the AT-2973SX, AT-2973T, and AT-2973T/4 Adapters
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adapter, the TCP/IP processing can be moved to hardware, freeing the
CPU for more important tasks such as application processing.
CPU for more important tasks such as application processing.
The Broadcom NetXtreme II adapter's TOE functionality allows
simultaneous operation of up to 1024 fully offloaded TCP connections for
1-Gbps network adapters. The TOE support on the adapter significantly
reduces the host CPU utilization while preserving the implementation of
the operating system stack.
simultaneous operation of up to 1024 fully offloaded TCP connections for
1-Gbps network adapters. The TOE support on the adapter significantly
reduces the host CPU utilization while preserving the implementation of
the operating system stack.
Internet Small
Computer
Systems Interface
(iSCSI)
The IETF has standardized the Internet Small Computer Systems
Interface (iSCSI). SCSI is a popular protocol that enables systems to
communicate with storage devices, using block-level transfer (that is,
address data stored on a storage device that is not a whole file). In
addition, iSCSI maps the SCSI request and response application
protocols and its standardized command set over TCP/IP networks.
Interface (iSCSI). SCSI is a popular protocol that enables systems to
communicate with storage devices, using block-level transfer (that is,
address data stored on a storage device that is not a whole file). In
addition, iSCSI maps the SCSI request and response application
protocols and its standardized command set over TCP/IP networks.
As iSCSI utilizes TCP as its sole transport protocol, it greatly benefits from
hardware acceleration of the TCP processing (that is, use of a TOE).
However, iSCSI as a Layer 5 protocol has additional mechanisms beyond
the TCP layer. iSCSI processing can also be offloaded, thereby reducing
CPU utilization even further.
hardware acceleration of the TCP processing (that is, use of a TOE).
However, iSCSI as a Layer 5 protocol has additional mechanisms beyond
the TCP layer. iSCSI processing can also be offloaded, thereby reducing
CPU utilization even further.
The Broadcom NetXtreme II adapter targets best-system performance,
maintains system flexibility to changes, and supports current and future
OS convergence and integration. Therefore, the adapter's iSCSI offload
architecture is unique as evident by the split between hardware and host
processing.
maintains system flexibility to changes, and supports current and future
OS convergence and integration. Therefore, the adapter's iSCSI offload
architecture is unique as evident by the split between hardware and host
processing.
Power
Management
When the system is down and waiting for a wake-up signal, the adapter
speed connection may be at 10 Mbps or 100 Mbps. However, it can return
to 1000 Mbps when the system is up and running if it is connected to a
1000 Mbps capable switch. For this reason, connect systems that use the
Wake on LAN (WOL) feature to a switch capable of both 1000 and 10/100
Mbps speeds.
speed connection may be at 10 Mbps or 100 Mbps. However, it can return
to 1000 Mbps when the system is up and running if it is connected to a
1000 Mbps capable switch. For this reason, connect systems that use the
Wake on LAN (WOL) feature to a switch capable of both 1000 and 10/100
Mbps speeds.
Wake on LAN
(WOL) Feature
The WOL feature sets the speed at which the network adapter connects to
the network while the adapter is in Wake on LAN (WOL) mode which is
enabled automatically. The default speed for WOL mode is 100 Mb. An
adapter can negotiate speeds between 10 Mb and 100 Mb. You cannot
configure this feature because it is enabled automatically.
the network while the adapter is in Wake on LAN (WOL) mode which is
enabled automatically. The default speed for WOL mode is 100 Mb. An
adapter can negotiate speeds between 10 Mb and 100 Mb. You cannot
configure this feature because it is enabled automatically.
Note
The WOL feature is supported on the AT-2973T and AT-2973T/4
adapters. It is not supported on the AT-2973SX adapter. For more
information, see “Limitations” on page 66.
adapters. It is not supported on the AT-2973SX adapter. For more
information, see “Limitations” on page 66.