| Although the FDDI is shown as a bus in the LAN interconnect window,
as you say it's actually a ring with point-to-point connections. By
obscuring the physical topology (at least in this window), HUBwatch
makes it easy to set it up as a LAN.
> HUBWATCH you have only used 1 channel. FDDI is point to point however.
> Does this mean in reality that 2 channels (2 groups of 6 wires) have
> been used (B-A,B-A)?
If you consider setting up the equivalent with wires, note that even
receive and transmit are separate for each connection. This takes up
4 channels as far as I can remember.
> The next config really confused me.
>Go into the FDDI ring display and
> each A port, on all 3 bridges, shows it's connected to a B port
> and each B port shows it's connected to an A port.
Again consider the same with wires. You would need a wire
from A(1) to B(2), A(2) to B(3), and A(3) to B(1). This should
take up 6 backplane channels in all, allowing for rx/tx.
> By the fact the the FDDI ports are port 1, you do not have a lot
> of control as how AB connections are made. Some but not a lot.
> Maybe it's for the better? 8^)
Why does FDDI being bridge port 1 affect how much control you have
over A and B? Note the difference between the PHY ports and bridge
ports. It certainly is for the better.. as you can imagine
it would be a lot harder to set up FDDI without the LAN abstraction.
Anil
|
| > If you consider setting up the equivalent with wires, note that even
> receive and transmit are separate for each connection. This takes up
> 4 channels as far as I can remember.
What you're saying is that an A to B port connection will use 2
channels or 12 wires. Bye, bye 14 channels real fast if doing DAS
and lots of FDDI modules, etc.
> Again consider the same with wires. You would need a wire
> from A(1) to B(2), A(2) to B(3), and A(3) to B(1). This should
> take up 6 backplane channels in all, allowing for rx/tx.
Which is supported now, tree or DAS in the hub? I thought it was
tree. If it's a tree then wouldn't the A(3) to B(1) connection
not be made as that would be a DAS dual ring? And with that shouldn't
one green LED be out on the front to indicate no connection? As
it was both A and B port LEDs were green for all FDDI ports.
> Why does FDDI being bridge port 1 affect how much control you have
> over A and B? Note the difference between the PHY ports and bridge
> ports. It certainly is for the better.. as you can imagine
> it would be a lot harder to set up FDDI without the LAN abstraction.
I kinda like the way it's done. Removes the guess work out of
configuring FDDI's. It's just that I had bridge #1 with it's A
port into the hub and B to the front. The #1 port for this bridge
was connected to a FDDI LAN. I tried to reconfigure both A and
B into the hub without first removing #1 from the FDDI LAN and I
got a SNMP SET FAILED error message.
It's probably just a case of being really sure of your LAN topology
before you click. Especially with FDDI.
dave
|