Cisco Security Agent (CSA) was an endpoint intrusion prevention system made originally by Okena (formerly named StormWatch Agent), which was bought by Cisco Systems in 2003. The software is rule-based and examines system activity and network traffic, determining which behaviors are normal and which may indicate an attack. CSA was offered as a replacement for Cisco IDS Host Sensor, which was announced end-of-life on 21 February 2003. This end of life action was the result of Cisco's acquisition of Okena, Inc., and the Cisco Security Agent product line based on the Okena technology would replace the Cisco IDS Host Sensor product line from Entercept. As a result of this end-of-life action, Cisco offered a no-cost, one-for-one product replacement/migration program for all Cisco IDS Host Sensor