Backup Exec remote agent installation requirements

Hi, our customer's BE server is Backup Exec 2014 SP2 on Windows Server 2008 R2 SP1 Std. All clients are Windows clients (Windows 7 SP1 or Windows Server 2008 R2 SP1).

The customer wants to do push installation of agent from BE server to all the clients. However, we tested and found some of the clients are able to be pushed install and some failed the push installation. Customer told us their clients are all in the same network (same subnet). 

May I know what are the requirements for push installtion of Windows agent to the clients? And if the push installaton failed on the client, how should we troubleshoot?

Thanks in advance.