Allied Telesis NETEXTREME II AT-2973SX - Manual (Page 165)

AT-2973SX, AT-2973T, and AT-2973T/4 NetExtreme II Family Adapters Installation and User’s Guide
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D2 PHY Loopback Enables PHY loopback mode in the adapter
and transmits 5000 Layer 2 packets of various
sizes. As the packets are received by
Broadcom NetXtreme II User Diagnostics,
they are checked for errors. Packets are
returned through the PHY receive path and
never reach the wire. The adapter should not
be connected to a network.
D4 LSO Verifies the functionality of the adapter's Large
Send Offload (LSO) support by enabling MAC
loopback mode and transmitting large TCP
packets. As the packets are received by
Broadcom NetXtreme II User Diagnostics,
they are checked for proper segmentation
(according to the selected MSS size) and any
other errors. The adapter should not be
connected to a network.
D5 EMAC Statistics Verifies that the basic statistics information
maintained by the chip is correct by enabling
MAC loopback mode and sending Layer 2
packets of various sizes. The adapter should
not be connected to a network.
D6 RPC Verifies the Receive Path Catch-up (RPC)
block by sending packets to different transmit
chains. The packets traverse the RPC logic
(though not the entire MAC block) and return
to the receive buffers as received packets.
This is another loopback path that is used by
Layer 4 and Layer 5 traffic within the MAC
block. As packets are received by Broadcom
NetXtreme II User Diagnostics, they are
checked for errors. The adapter should not be
connected to a network
Table 9. Diagnostic Tests (Continued)
Test
Description
Number Name