Ken,
From the remote server in question, I am able to ping the media server. From the media server, I am able to ping the remote server. Both instances, I ping both IP and hostname.
On the remote server, Remote Agent is installed and it's service started. FYI, I have uninstalled and reinstalled RA in the unsuccessful effort to resolve.
In addition, I have another remote server with RA installed. The media server detects and attaches to this server's hard drives without issue. Because this remote server is within the same AD OU and same subnet as the remote server in question, I do not suspect a firewall or routing issue.