You may say, here it comes another agent deployment troubleshooting idea, and you’d be absolutely right! In this case is specifically developed for the error 319:
Install protection agent on name.domain.com failed:
Error 319: The agent operation failed because of a communication error with the DPM Agent Coordinator service on name.domain.com.
Error details: The RPC server is unavailable (0x800706BA)
Recommended action: 1) Verify that name.domain.com is remotely accessible from the DPM server.
2) If a firewall is enabled on name.domain.com, make sure that it is not blocking requests from the DPM server. Refer to the DPM Deployment Guide for more information on configuring the firewall for DPM.
Additionally, the DPM-Alerts event log displays the following event:
Log Name: DPM Alerts
Event ID: 370
Task Category: None
Agent operation failed. (ID: 370)
The agent operation failed because of a communication error with the DPM Agent Coordinator service on name.domain.com. (ID: 319)
KB2981833 - System Center 2012 Data Protection Manager agent installation fails with error 319 (http://support.microsoft.com/kb/2981833)