How to interpret the following definition of OIDs in DDK?

NTDEV
1

Case 1. OID_GEN_RCV_NO_BUFFER
The OID_GEN_RCV_NO_BUFFER OID specifies the number of frames that the NIC cannot receive due to lack of NIC receive buffer space. Some NICs do not provide the exact number of missed frames; they provide only the number of times at least one frame is missed.

Case 2. OID_802_3_RCV_OVERRUN
The number of frames not received due to overrun errors on the NIC.

What is the meaning of each of the above?

I see atleast two cases where NIC misses an incoming frame.

Case a. There is receive buffers (physical memory to hold received frames) available on system, but the NIC/hardware (DMA copy)

is not fast enough to copy the incoming frames to host physical memory with the result that NIC hardware RX fifo overflows

ending up losing frames.

Case b. All Receive buffers present to hold incoming frames have been already used up and is currently present with app/tcp-ip/ndis protocol/miniport driver

and is not available for NIC hardware to copy the incoming frames to physical memory, ending up losing frames.

From the DDK documentation its not clear to me which OID (case #1, #2) corresponds to which situation described above (case #a, #b).

Does anyone know what does Microsoft mean by case #1, Case#2 respectively?

Pls reply.

Thanks,

-Praveen

2

If the WDK documentation is not sufficient consider looking into the WDK
sample miniport drivers and see how the Microsoft author decided to
interpret them.

Good luck,

Thomas F. Divine

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Praveen Kumar
Amritaluru
Sent: Thursday, January 24, 2008 9:35 AM
To: Windows System Software Devs Interest List
Subject: [ntdev] How to interpret the following definition of OIDs in DDK?

Case 1. OID_GEN_RCV_NO_BUFFER

The OID_GEN_RCV_NO_BUFFER OID specifies the number of frames that the NIC
cannot receive due to lack of NIC receive buffer space. Some NICs do not
provide the exact number of missed frames; they provide only the number of
times at least one frame is missed.

Case 2. OID_802_3_RCV_OVERRUN

The number of frames not received due to overrun errors on the NIC.

What is the meaning of each of the above?

I see atleast two cases where NIC misses an incoming frame.

Case a. There is receive buffers (physical memory to hold received frames)
available on system, but the NIC/hardware (DMA copy)

is not fast enough to copy the incoming frames to host physical memory
with the result that NIC hardware RX fifo overflows

ending up losing frames.

Case b. All Receive buffers present to hold incoming frames have been
already used up and is currently present with app/tcp-ip/ndis
protocol/miniport driver

and is not available for NIC hardware to copy the incoming frames to
physical memory, ending up losing frames.

From the DDK documentation its not clear to me which OID (case #1, #2)
corresponds to which situation described above (case #a, #b).

Does anyone know what does Microsoft mean by case #1, Case#2 respectively?

Pls reply.

Thanks,

-Praveen

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