Q: What would the cabling pin-out be between a Cisco and a TA using DDR? My interface comes up in SPOOFING mode when DCD is tied to DSR, even though the the TA provides DCD high to the Cisco. After the TA dials and connects to the remote end, the interface will not come up. It times out and drops the connection.
A: DSR should be swapped for DCD if the DCE device is supporting true v.25bis. V.25bis specifies that DSR is raised when a call connects. The router needs to see DCD raised, so you want to swap the DCD and DSR pins on one end of the cable.