Most manufacturers these days are not building multiple-fiber-port modules in the small footprint niche that the 3Com LANplex/CoreBuilder 2500 and 3500 occupied. Especially in the slower (10 or 100) speeds. No money to be made there.
I have replaced several 3Com LANplex and CoreBuilder switches that had 10Base-FL or 100BASE-FX fiber modules, with Cisco 10/100 UTP switches and rack-mounted media converters of the appropriate speed (10 or 100) and fiber type (MMF or SMF). Takes up a little more space in the rack, and requires extra power outlets for the media converter shelf, but it works fine.
In some ways, this approach is even more flexible: you can add or replace on a port-by-port basis, vs. swapping out a whole 8-port 10FL (2500) or 6-port 100FX (3500) module.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...