Network address translation rewrites packet addresses at a router, letting many internal devices share one public address. The router tracks which device opened each connection. Equipment behind NAT can reach the internet, but inbound remote access needs port forwarding, a VPN or a cloud relay.
NAT exists because public IPv4 addresses are scarce. It hides an internal addressing plan from the internet, and it makes every unsolicited inbound connection harder.
Why it complicates remote access
A router forwards an inbound connection only when a rule says where to send it. Static port forwarding exposes one device, a VPN keeps the recorder off the public internet, and a vendor relay keeps the session started from inside.
What to set up instead
Forwarding a camera port publishes that device to every scanner on the internet. Where remote viewing is required, prefer a VPN or the vendor relay, keep firmware current and give every device a unique password.
Related:Commercial security camera systemsGlossary: Remote access security