🚀 go-pugleaf

I just had a 4-wire, full duplex leased line installed between my
home and the university.  There's an RJ-11 jack where the phone
cord terminates and a powered box called a "Teltrend Data Station
Termination" which plugs into the RJ-11 jack and provides a RJ-11
jack of its own.

What does this box do and why is it necessary?  In the past, I've
connected leased-line modems to what looked like a simple 4-wire telco jack
without any extra electronics.  Also, since both ends use the same central
office, I was planning to use a pair of short-haul modems to support a 19.2kb
data rate (this has been successful with other installations in the past.)
Could this box (or any other telco-related factor) influence this?
Finally, I was going to purchase a pair of Gandalf LDS309A modems.
They run about $400 a piece; can anyone suggest anything possibly cheaper
which would work as well?

Please reply by mail, since I'm not on the Telecom list.  Thanks.
---
Steve Dyer
dyer@harvard.HARVARD.EDU
dyer@spdcc.COM aka {linus,wanginst,bbnccv,harvard,ima,ihnp4}!spdcc!dyer