3c905b buffering

Tommy McNeese mcneese@bcstechnologies.com
Fri Dec 3 10:47:07 1999


Does the 3c905b buffer TX packets in any way?
Here is the problem, we have 2 UDP packets being transmitted. The first one
is a broadcast and a second is to a specific machine. In the code they are
sent back to back, but the broadcast always seems to get the specific
machine about a quater of a second to second faster than the second
packet(I have not been able to figure out the actually delay yet). Network
traffic is low. Both are connected to the same hub, all at 10mbits.
This same problems happens on the Realtek RTL8139, but not on the SMC Ultra
card. All three cards where tested in the same machine. No errors are
reported.
The drivers where the following :
On Linux 2.2.5-15 system
3c59x.c:v0.99H 11/17/98
rtl8139.c:v1.04 9/22/98
On Linux 2.0.34 system
smc-ultra.c:v2.02 2/3/98
3c59x.c:v0.99H-WOL 2/24/99
rt18139.c:v1.06 3/16/99

If I send out a third packet, which is a broadcast packet, then the delay
goes away. All packets are under 100 bytes.

Thanks for any help.
Tommy
mcneese@bcstechnologies.com