The Firewall Services Module (FWSM)
- a high-speed, integrated firewall module that provides the fastest firewall data rates in the industry: 5 GB throughput, 100, 000 CPS, & 1M concurrent connections. Up to four FWSMs can be installed in a single chassis providing scalability to 20 GB per chassis. As part of the world-leading Cisco PIX Firewall family, the FWSM provides large enterprises & service providers with unmatched security, reliability, & performance. The FWSM leverages Cisco PIX technology & runs the Cisco PIX Operating System (OS), a real-time, hardened, embedded system that eliminates security holes & performance-degrading overhead. At the heart of the system, a protection scheme based on the Adaptive Security Algorithm (ASA) offers stateful connection-oriented firewalling. Using ASA, the FWSM creates a connection table entry for a session flow based on the source & destination addresses, randomized TCP sequence numbers, port numbers, & additional TCP flags. The FWSM controls all inbound & outbound traffic by applying the security policy to these connection table entries.