D-Link Monday fortified its NetDefend security product line for small and midsize businesses with new firewall products and a security appliance, a company spokesman said.The new firewalls, the D-Link NetDefend Firewall\/VPN Applications, or the DFL-800 and DFL-1600, combine stateful packet inspection functionality offered in currently available NetDefend firewall products with content filtering and intrusion detection and protection, said Rocky Rosas, technical marketing engineer with D-Link."Essentially, what we've done is created some high-performance security platforms that combine different types of security functions into a single product," he said.The NetDefend Application Security Gateway, or DFL-M510, adds new functionality to D-Link's security line, Rosas said. The product is an application security gateway that monitors and enforces a company's network policies at the application level, he said. An SMB can install the product to sit between any standard firewall and the external network to apply Internet usage policies to network traffic."It goes down to the application level in terms of monitoring and blocking traffic that comes into and out of your network," Rosas said.For instance, an SMB can use the DFL-M510 to block its employees from using instant-messaging software, or from using peer-to-peer software that could make the network vulnerable to intrusion, he said.The DFL-800 firewall supports 10\/100Mbps\u00a0connections and up to 25,000 concurrent network sessions. The DFL-1600, which supports up to 400,000 concurrent sessions, supports six gigabit Ethernet connections.The suggested retail price for the new firewalls and the gateway are as follows: $1,699 for the DFL-800, $6,999 for the DFL-1600 and $2,799 for the DFL-M510. All three products are available now from D-Link's distribution and reseller partners.D-Link expanded its wireless and wired network product line to include security products in 2003, Rosas said. The company recently unveiled a VoIP\u00a0network offering, and plans to offer storage products beginning next year, he said.