Final answer:
The term for the ability to perform packet inspection at Layer 3 based on IP addresses and port numbers is known as a Network Layer Firewall or Stateful Packet Inspection (SPI).
Step-by-step explanation:
The term that describes the ability to perform packet inspection at Layer 3 based on the source and destination IP addresses, and source and destination port numbers, is typically referred to as Network Layer Firewall or Stateful Packet Inspection (SPI). This technology allows a firewall to inspect incoming and outgoing packets to determine whether they should be allowed through or not, based on a set of security rules. These rules can include checks on the packet's source and destination IP addresses, and their corresponding source and destination port numbers. The firewall can keep track of active connections, and can allow or block packets based on the state of the connection, which is a key feature of SPI.