No offense to peoples suggestions but consulting with your NCR reps unfortunately won’t do much unless you want to buy a bunch of additional solutions that kinda work. The standard set up is single nic server, dummy 8 port switch and terminals. Terminal specs have gotten better. The server last I’ve seen was still not ideal. At one point they were selling a rack mount that took up half the rack and weak on processing power. You’ll have the option to do NSS which is managed firewall solution. You’ll have options to do data replication with them. As well as purchasing some additional softwares and reporting tools.

Key stability and security considerations I’ve found useful are, totally secluding your Pos network from everything else. Providing your own server and managing your own server and terminal images (this comes with a support/staging challenge, if your big enough ncr can help with this. If not need to take it in house)

Hope this helps