I'd like to think I have a good understanding of NAT and Firewall rules at a basic level, though please correct me if I'm wrong at any point. I've seen many products list their firewall requirements as needing ports allowed 'both ways'.
In particular I'm talking about the requirements listed here; http://mysignageportal.com/cdms/support/faq/what-information-do-i-need-if-there-are-restrictions-in-place-on-my-network.html
The following ports are required to be open both ways for complete communication with the CMS server
I understand allowing the ports outbound from our LAN to WAN on the firewall. However when it states both ways - wouldn't that require NAT on our WAN IP pointed to the LAN IP on the ports listed? The idea is to have many of these devices in our LAN so not sure how a 1:1 NAT rule could work there. I don't think they mean NAT, but need to be sure I'm not missing something here.
Would you say it's just their documentation that's lacking?
Does it just mean to allow it on the established connection when the LAN device sends traffic outbound? If so I've never seen a firewall rule to disallow an inbound response to an established connection.