NBU ports discussion

In NBU 6.x - 7.0, PBX was only used for comms between master and media server(s).
Servers used vnetd to connect to clients. If vnetd failed, it would fail back to bpcd.

From NBU 7.0.1 onwards, comms to 7.x and 6.x clients will be tried as per the section under this topic in above TN:
NetBackup 7.0.1 Considerations 

This means that 7.1 server connecting to 6.x client will be exactly the same - 1st try pbx (which will fail), then fail back to vnetd. If still not successful, it will try bpcd.

Exact same ports will be used for clients behind firewall.

In a production environment, it is very easy to see port connection attempts with bptestbpcd command on master and/or media server:

Connection test to a client:
bptestbpcd -client <client-name> -verbose -debug

Connection test to a media server:
bptestbpcd -host <server-name> -verbose -debug