If your telco's LTU doesn't terminate in Ethernet, the first avenue of investigation has to be getting a better telco. Failing that (or if running your own dark fibre or whatever), then yes, you do need a T1 or X.21 or whatever to Ethernet bridge, possibly even from Cisco, but that constitutes evidence of collusion between your telco and the "enterprise" networking vendors, not of any technical need. The first company I worked at that had an Internet connection, found that we had to spend £1500 on a Cisco "router" because the British Telecom LTU didn't terminate in RS232 or Ethernet or anything sane like that which we could just run into the Linux firewall, but in X.21. And that for a just 64kbps leased-line!


144-port switches aren't cheap. But considering that the router-to-WAN connection won't be faster than Gbit Ethernet, the switch-to-router connection needn't be any faster than that either. In other words, there's no particular reason to build the switch into the router. (Which would also mean that the box with the switch itself in wouldn't be Internet-facing, and so you might be less worried about firmware updates being EOL'd.)

Peter