PVA's port field in search request makes it not NAT/firewall friendly

[gilesknap]

Hi @mdavidsaver

I'd like to get your views on this https://github.com/epics-base/pvAccessCPP/issues/197 please.

Is this an issue with the PVA protocol itself or is there a way to make PVA search requests via a NAT?

Many thanks, giles