SPI

SPI

Stateful Packet Inspection. A firewall mechanism which examines each incoming network packet and only allows through those packets which are for a known open connection.

For more information see:

• www.firewall-software.com/firewall_tech/stateful_packet_inspection.html - Description of Stateful Packet Inspection.
• http://everything.explained.at/Stateful_firewall/ - Stateful Firewall Explained.