The new technology comes as other vendors, both complementary and competitive, strengthen their own network control initiatives.
NAC is a network-based approach to authenticating and enabling access to users and services across a network.
Cisco's latest NAC appliance handles various network connection methods, including remote access, wireless and traditional wired network deployments.
Rohit Khetrapal, Cisco's director in charge of NAC Appliance, said that the new device now allows for deployment both inline or out of band.
"What we've done is added layer 3 out of band and what that does is allow for a centralized deployment model," Khetrapal told internetnews.com.
The new device also provides for single sign on for VPN clients, as well as Windows Active Directory domains.
Microsoft has its own NAC-like initiative, called NAP (Network Address Protection), which is set to appear in Windows Vista.
Thanks to a 2004 deal, NAP and NAC will work with each other. But there are also competitive NAC solutions from other vendors.
Among them are Juniper Networks and the Trusted Network Computing (TNC) Group, which provides Cisco NAC alternatives.
Typically NAC requires some form of hardware to help implement it. But NAC vendor InfoExpress has a Dynamic NAC offering (DNAC) that takes a peer-to-peer approach.