Looking at buying a Adtran Total Access 908 Mfg# 4212908L1 to handoff to a PRI Circuit. The service provider does not handoff to a PRI. We are getting 500 upstream/500 downstream with sip trunking. They are going to provide a Cisco ASR1001 router to handle the data. I want to make sure I can set the Adtran in place with the ASR1001 and not have any issues with handing off to the PRI Circuit. I know there is programming involved, I just want to make sure this is a reliable setup.
Yes, that's exactly what it is made to do!
In addition to the PRI, you'll also have up to eight POTS FXS interfaces should you need them.
You're correct that some programming (configuration) will be needed. You'll need to know the IP parameters, SIP parameters, and PRI/PBX parameters.
You do NOT want the Ethernet interface of the TA 908 behind a NAT on the Cisco. Make sure that your service provider gives you a public IP address for it. It should work fine, we have dozens of them in service.