Asterisk and cisco at186

I am setting up a new Asterisk box
using 2 ata186 for testing. Asterisk is talking to and registering the ata’s. If I pickup one up to call the other it rings the other box. But, when I pick it up the calling phone goes to a fast busy. This happens when I call either way!! A message on the asterisk machine says “sip response 481 call leg/transaction does not existing back from” 10.10.1.80″
For my test both ata’s are DHCP and the pbx is static all on the same switch

Any thoughts??

I am using the ATA186 setting per John Todd

Thanks KEN

ken@tpctechnologies.com