RE: DACS Equipment

I have a number of mux DS-3s coming in - right now they drop straight
into aggregation routers. What I like to do is drop them into
a local DACS
and comb them out to DS-1s and then re-mux them back on to
internal DS-3s.
This will let me move circuits around digitally inside our equipment.

You're looking for digital cross connect, for the most part.
You should take a look at the Cisco line i.e. 15454 et. al.

You can bring in ds3, groom on the backplane, and send out
ds3. I've used the 15454 et. al. in production and for your
stated purpose it's more economical than buying some big iron.

You may also want to consider your physical layer architecture
if you do this i.e. interconnecting vs. cross connecting so that
you have test access where you need it. IIRC, the 15454 et. al.
will do passive monitoring at a line level and will SNMP alert
on outages down to the smallest mux' unit. Very nice for the IP