FDDI or 100Mb Ethernet

FDDI would be my last choice. 100MB ethernet can be run full duplex, is
less expensive, and far easier to troubleshoot.

FDDI can run full duplex, as for the other two things its a matter of
opinion & conditions. (One I agree with, but still opinion).

-Deepak.

For desktops, I agree completely that fast ethernet is the way to go. Fast
ether hubs are cheaper and easier to wire than cddi hubs (no cross over
cables required).

For a backbone, though, I would point out that FDDI is a token ring
protocol, so performance is always predictable. Ethernet, and fast ethernet
have performance knees. (Actually, I'm assuming Fast Ethernet will have a
knee at around 70% utilization. I haven't tested that it really does).
Also, both Fiber and Copper can be implemented with dual attached rings
which might be an advantage for a backbone link.

    --Dean

Okay. Playing my usual devil's advocate role, please tell me what
migration path lies beyond FDDI for faster connectivity?

- paul

I have started to look at "Fast Ethernet" and see "Full-Duplex
Switched Fast Ethernet". I mean, the switch ports are SO cheap,
why do anything less...

Depends on the switch. Some switches, (notably Bay 28115Rs) perform
poorly in fast ethernet/full duplex mode whereas they perform like champs
in half-duplex mode. What they say they "do", and what they really do
well are sometimes not the same thing.

-Deepak.

It's even cheaper to cascade 10mbps/repeaters off of hdx switch 10's
and aggregate them into 100's.

Regards,

10Mbps switches with 100Mbps FDX uplink ports are rather cheap these days.

Just use those and fergit about it; your backbone is then 100Mbps FDX, and
the drops are either switched 10 or 100Mbps (depending on where you drop
from).

We have been smurfed at *sustained* rates in excess of 70Mbps (two full-bore
DS3s worth - peaks right up at 44.7 X 2) and haven't managed to saturate this
back-office network fabric :slight_smile:

Want a second free tip? CMD RAID controllers :slight_smile:

I have started to look at "Fast Ethernet" and see "Full-Duplex

   >Switched Fast Ethernet". I mean, the switch ports are SO cheap,
   >why do anything less...

   It's even cheaper to cascade 10mbps/repeaters off of hdx switch 10's
   and aggregate them into 100's.

Yeah, and then you can network a whole office building that way (who
needs messy routers anyway?)... and be surprised when you discover
that your 10mb ether segments are at 30% utilization in the middle of
the night due to SAPs from Novell servers. And wonder why
productivity goes to zero in the middle of the afternoon as the dark
clouds of a broadcast storm gather in the west.

No, I don't know of any Fortune 500 corporations in my immediate area
whom this has happened to.

                                        ---Rob

Paul Ferguson <ferguson@cisco.com> writes:

Okay. Playing my usual devil's advocate role, please tell me what
migration path lies beyond FDDI for faster connectivity?

SM FDDI -> SM POS. Problem solved. Reuse your fibre, even.

Your inventive marketing friend,

  Sean.