The ATLAS does support IP routing. If you want to pass IP traffic across a T1 interface, you can set up either Frame Relay or PPP as the layer 2 protocol across it.
The ATLAS does not support SIP, but you can connect FXS ports to a point-to-point T1, and then have FXO ports on the other end of the circuit.
I'm afraid I'm unclear by what you mean by "copper dry line handoffs." If those are FXS lines then "maybe" depending on whether you want PLAR or for the ATLAS to provide dial tone and let you dial a number.
But the ATLAS does support IP Routing, so if it is a point-to-point then each side needs to be on a different IP network.
Let me know if you have more information or additional questions,
What I actually need to know is can an Atlas 550 do IP to IP between two Octal E&M module (Part number 1200313L1) as opposed to using a T1 PRI module. Thanks again.
Ah. The answer to this one is easy - no. You cannot map IP to the E&M Module. It is an analog interface.
The ATLAS can do IP Routing to a T1 interface (or fractional T1) or a serial interface (such as the V.35 module).