Setting up backup network - What type of port Group

I am designing an isolated backup network that will backup my ESXi 5.0 datacenter via vcenter using Symantec backup Exec 2013.  thsi network will be attached to a dedicated backup storage appliance.  I cannot find any information on designing such a network. I want to know if the vSwitch/port group needs to be a VM port group and if it needs to be connected to each guest via a virtual nic, or if the API uses the vMotion port group via the host.  Also, I assume my vCenter physical host needs to be connected to this same network via a second NIC as well.  Does anyone have a best proctice or configuration guide for setting up such a network