VM backup in DMZ

Hi experts,

I need to backup  VM servers located on an ESX in DMZ. The cell Manager  and Vcenter is in intranet.

What all ports I need to open from Cell Manager to the ESX in both directions. Is opening 443 sufficient enough between Cell manager and DMZ ESX server or port 902(bidirectional) is also required. 

Thanks in advance

Regards

Raj