Filter
Top Products
100VG-AnyLAN Training
B-4
8) The driver now waits for a status interrupt. The MASK7 bit in the NetMask
register must be set for the status interrupt to reach ThunderLAN.
9) When this interrupt arrives, perform frame exchange
Training involves the exchange of 24 consecutive training frames between the
client and the hub. The client begins by sending a training frame. The hub an-
swers with the same frame, except in the Allow config field. The client verifies
that the received frame is a valid training frame. This process continues until
24 successful consecutive frames are exchanged.
The 802.12 standard states that these 24 frames must be exchanged within
a training window of 48 frames. If this fails, training may or may not be possible
within this window. The client must ensure that there are enough frames left
in the window for successful training. If this is not possible, the client must re-
quest a new training window and try again. The process is shown below:
Figure B–2. Training Flowchart
Yes
No
No
Yes
No
Yes
training
Restart
Training successful
Training failed
?
window
training
24 more in
we send
Can
?
frames
consecutive
24
?
frame OK
Is
Receive frame
Send frame
To determine whether the training frame received from the hub is correct the
driver should:
Check that the destination address is a null
Check that the training frame has the adapter’s address for the source ad-
dress. This is not required, but is good practice.
Check the first 55 bytes of the data field (optional private protocol informa-
tion area as defined in 802.12). They should be null.