How to separate backup traffic in virtual switches

I am using Avamar backup agents on ESXi 5.1 with distributed virtual switches.  Avamar uses proxy agents on each cluster to assist with the backup traffic.  Avamar proxy agent is on esxi host 1.  The virtual machine I'm backing up is on ESXi host 2.  When Avamar backs up the virtual machines on host 2 , I want the traffic to flow in such a way that it is separated from other virtual machine traffic and management traffic on host 1and from other management traffic on host 2.

To separate traffic, do I need to create a separate port group on esxi host 1, or a separate vmkernel port on host 2, or both?

Thanks