Both TDM and DevTest are in the same network and have firewalls disabled. I was able to ping them, telnet the main ports from each side and open both Portals in both machines.
When I try to configure the DevTest Portal information under the Configuration --> DevTest Portal page in the TDM Portal, the message "Failed to connect to DevTest Portal with the provided details. Do you still want to save the configuration"?
I don't proceed after that. I am using the standard 1507 port for DevTest portal and user admin with admin password.
Release : 4.8.1
Component : CA Test Data Manager