| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 1883.1 | | NETCAD::STEFANI | Machines to humanize | Wed Nov 29 1995 18:40 | 13 |
| >>1. Does this set the filtering at the NIC level or is the DLI
>> software doing the multicast filtering? I would like to do the
>> filtering as efficiently as possible.
I don't know anything about the DLI interface, but I can tell you that
the DEFPA supports a 64 entry CAM (2 entries are reserved, leaving 62)
for adding unicast and multicast addresses. The cards use perfect
filtering so that the upper layer SW does not need to filter on
multicast addresses. Of course, there are programmable filters for
enabling unicast and/or group address promiscuous mode. Under those
conditions the upper layer SW would be getting a lot of extra frames.
-Larry
|
| 1883.2 | Which Manual? Still DLI curious. | PRIME3::THOMAS | | Thu Nov 30 1995 11:53 | 10 |
| Thanks for your help on the DEFPA. What manual(s) can I consult
on how to set the filters on the DEFPA? Can I set these while doing
IO? Can I add/remove a single filter. See existing filters being
used?
Mike Thomas - curious in Linthicum, MD.
P.S. I'm still curious about the DLI capabilities and behavior with
reguard to multicast address filtering.
|
| 1883.3 | | NETRIX::thomas | The Code Warrior | Thu Nov 30 1995 14:36 | 2 |
| DLI has a limit of a 256 multicast addresses per interface.
You can change multicast anytime after the socket has been bound.
|
| 1883.4 | NIC or DLI does the filtering | PRIME3::THOMAS | | Thu Nov 30 1995 17:25 | 28 |
| Since the NIC has a limit of 62 filters and the DLI 256 filters,
is the filtering done within DLI exclusivly done in the DLI software
with no filtering being done by the NIC? Or, are the first 62 filters\
programmed into the NIC and the remainder implemented in the DLI
software?
Am I correct in assuming that to optimize performance, the NIC filters
should be used? If the NIC/DLI filters are totally independant, can I
get 62 in the NIC and another 256 in the DLI?
What are the performance issues associated with a large collection
of filters (for both the NIC and DLI.) I assume that it takes time
for either to check each incomming packet against the list of filters -
is this correct? I suspect the performance concern would be the
greatest for the DLI. Will the filters affect throughput or CPU
utilization because of the need to check the list of filters each time?
I have to support a very high bandwidth utilization on the FDDI and I
am looking for any way possible to increase efficiency.
Thank you for your help. The manuals say WHAT the software will do and
what the interface is but obviously not HOW a feature is implemented.
Also often missing are the ramifications of utilizing a feature.
That's why the assistance on this forum is invaluable.
Greatfully yours,
Mike Thomas
|
| 1883.5 | | NETRIX::thomas | The Code Warrior | Thu Nov 30 1995 19:53 | 5 |
| DLI "refilters" what the NIC sends so a user will get only packets he
asked for. So your limit is the ~60 in DEFxA -- once that limit is hit,
the underlying services that DLI uses will return ENOSPC which DLI will
return to the user. Which means you are limited to the 60 or so ones
left.
|
| 1883.6 | OK,fine! - Summary | PRIME3::THOMAS | | Fri Dec 01 1995 10:31 | 12 |
| Thanks for all your help.
In summary:
The DLI does multicast address filtering via the NIC and is thus
limited to 62 filters on a DEFxA. These filters can be modified
anytime after binding.
Now I'll go play with it and watch it strut its stuff!
Mike Thomas (:>)-<--<
|