quoted

It's not clear why 19 or 20 were suggested as possible values.  I
checked back to 2.6.18 and MAX_SKB_FRAGS there is (65536/PAGE_SIZE +

2)

Because the check is >= MAX_SKB_FRAGS originally and James Harper told
me that "Windows stops counting on 20".

I've obviously not been clear enough here... GPLPV stopped counting at 20 (only needed to know if <20 or not). Windows itself can submit a packet to NDIS with hundreds of buffers. It doesn't really matter if it's 21 or 1021, I just didn't want to be misquoted.

James