IBM SC30-3681-08 manual Missed frame, Bits not set, Output frame counters DMA/FIFO underrun errors

Con®guring the X.25 Network Interface

Missed frame

When a frame arrives at the device and there is no buffer available, the hardware drops the frame and increments the missed frame counter.

L & F bits not set

On serial interfaces, the hardware sets input-descriptor information for arriving frames. If the buffer can accept the complete frame upon arrival, the hardware sets both the last and ®rst bits of the

frame, indicating that the buffer accepted the complete frame. If either of the bits is not set, the packet is dropped, the L & F bits

not set counter is incremented, and the buffer is cleared for reuse.

Note: It is unlikely that the L & F bits not set counter will be affected by traffic.

Output frame counters:

DMA/FIFO underrun errors

The number of times the serial interface card could not retrieve data fast enough from the system packet buffer memory to transmit them onto the network.

Output aborts sent

The number of transmissions that were aborted as requested by upper-level software.

Chapter 27. Con®guring and Monitoring the X.25 Network Interface 359