| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 3501.1 | Please provide further config info on bridge | NETCAD::BRAGDON | | Wed May 01 1996 15:52 | 15 |
| Mike,
Is the DEFBA in the DEChub900 being used to switch (bridge)
separate Ethernet segments in the backplane?
The first answer you received seems to be based on that possibility.
The second answer assumes a literal interpretation of your drawing.
Please advise.
BTW, the NETdesigner V1.9 design and validation tool will give
you answers, too. Just draw the network (use a 900EE in place
of 900EF in the backplane) and run validation.
Dave
|
| 3501.2 | Tried NETdesigner more questions | SIOG::M_CONNOLLY | | Thu May 02 1996 05:38 | 15 |
| Dave,
Yes the DEFBA is being used to switch seperate ethernet segments in
the backplane. Unfortunately I have now run out of backplanes. This
means that as in the diagram shown, both of the hub 90s will be connected
to the same ethernet in the dechub 900. I got a copy of NETdesigner and
it invalidates the network on the basis of the max number of segments
and the max number of repeaters. This would indicate that NETdesigner
is counting the the repeaters in the hub 90 as 2. I always believed
that ANY two number of repeaters in a dechub 90 counted as one.
Regards,
Mike
|
| 3501.3 | The DEChub 90 thinwire count of 2 is correct | NETCAD::BRAGDON | | Thu May 02 1996 08:10 | 19 |
| Mike,
The repeater count of 2 in your DEChub 90 is correct.
You have to count the 90FS repeating onto the thinwire
in the DEChub 90 as well as the DETMR repeating out a
front panel port.
In the DEChub 900, if you use the backplane flex channel,
you save a repeater count, as that technology does not
use the overhead of repeating (preamble, timing, etc).
But, if you were to use the thinwire in the 900, you would
get a "hop" onto the wire, just as in the 90.
BTW, did your drawing pass Model II in NETdesigner? When I used
300 meter lengths for your fiber links it showed a round trip
delay of 428 bit times. But the interpacket gap shrinkage was
a risky 48.5, typical of CSMA/CD domains with high repeater counts.
Dave
|
| 3501.4 | hops/foirl | SIOG::M_CONNOLLY | | Thu May 02 1996 08:55 | 15 |
|
In this case we are using the DEFMM to repeat between the hubs 90s so
the traffic dos nt hit the 900 backplane.
.
If the Fibre link between the DEFMI AND THE DEFMM are Foirl does this
not effect the hop and segment count. Our config is similar to that in
the Open DECconnect Application guide page 3-41.(except that they use a
Hub 900 as one of the remote hubs).
Is the HUB 90 backplane connection considered to be a hop?. Net
designer counts our config as 5 repeaters and 6 hops.
regards,
Mike
|
| 3501.5 | Further remarks... | NETCAD::BRAGDON | | Thu May 02 1996 12:51 | 13 |
| 1. FOIRL versus 10BaseFL wouldn't effect the repeater count, or
segment count. It would effect RTD (because segment type is an input
to the calculation. But as far as I'm aware, the 90FS fiber ports
support only 10BaseFL. The 900FP ports support 10BaseFL/FOIRL ST style
connectors.
2. Model I analysis of your User A to User B path is 5 repeaters, and 6
segments (2 mixing and 4 link), and thus fails IEEE 802.3 Section 13
Model I.
I hope this helps.
Dave
|
| 3501.6 | Minor correction - 90FS does in fact support FOIRL.. | NETCAD::BATTERSBY | Don't use time/words carelessly | Thu May 02 1996 13:06 | 6 |
| The DEFMI (DECrepeater 90FS) does support FOIRL on its 2 fiber
ports. Check out both the 1995 Network Products Guide on page 2-30
and in the 1996 Network Products Guide on page 1-21. The 90FA, 90FL,
and 90FS all are backwards compatible with FOIRL.
Bob
|
| 3501.7 | Thank you Bob. | NETCAD::BRAGDON | | Thu May 02 1996 16:36 | 2 |
| Thanks, Bob. I'm out sick and couldn't look that up today.
Dave
|