
I found a cheap ISDN simulator on ebay (got lucky on that one, most aren't cheap), a cheap Terminal adapter, and coupled them with my 3com RAS 1500.
The best I've been able to get is 46.6K down and 31.2K up with a LAN ping of 90-100 ms. I was hoping to get pings closer to 50 ms but, I guess it's just not possible with a dial-up modem.
I saved about 10 ms in latency over my purely analog setup
