Desktop software inventory

At the time of this writing, Cisco IOS Software included NBAR PDLMs for 98 of the most common network applications, with the capability to define an additional 10 applications using custom PDLMs.

Of these protocols, 15 require stateful packet inspection for positive identification. Because NBAR operates in the IP Forwarding switching path, only the first packet within a flow requires stateful packet inspection, and the policy is applied to all packets belonging to the flow. NBAR stateful packet inspection requires more CPU processing power than simple access control lists (ACLs). However, on newer branch router platforms, desktop software inventory has shown the overhead of enabling NBAR classification at dual-T1 rates to be quite minimal (typically 2 to 5 percent, depending on the traffic mix).