Firewall Concepts

firewall

is a controlled gateway between two networks. A firewall limits external client connections to a set of restricted ports on one or more computers that are inside the firewall.

Web servers and other network applications can also use firewalls to limit access to servers. SAS/CONNECT permits TCP/IP connections between clients outside a firewall to a spawner that runs on a SAS/CONNECT server inside a firewall.

socket inheritance

enables the server session to inherit the socket that the spawner uses to communicate with the client session. The socket is then used for subsequent communications between the client and the server session. Socket inheritance is significant because a single port can be used for starting an unlimited number of server sessions.

Before this innovation, a separate port was opened for each client that connected to a server by using a spawner. Socket inheritance limits the number of ports that are used for connections through a firewall, which improves the security of a firewall configuration and simplifies administration of a firewall configuration.