PacketHound is a product that aims to help an enterprise regulate traffic that might otherwise slow services down for all users of a local area network. PacketHound is intended to address the concern of businesses and universities about the downloading of large files, especially music files in the MP3 format, using Napster, Gnutella, and similar approaches. PacketHound can also monitor and reduce the number of streaming media files that are downloaded by network users. Both businesses and universities are concerned not only about such traffic slowing down the network for other uses, but also about the possibility of being sued by music companies for loss of intellectual property. According to Palisade Systems, the developers of PacketHound, Napster and Gnutella traffic has had a significant effect in performance on a number of university networks.
Although Gnutella uses a known port number that a network firewall server could screen for, the port number can be changed by a sophisticated user. The makers of PacketHound claim to be the only product that can monitor and block certain traffic based on the characteristics of the request and response flow, although they do not describe their approach in detail. PacketHound customers can also use the product to monitor without blocking and to also permit or block given traffic at different times of the day. PacketHound is not installed in a firewall server but as a separate PC with an Ethernet card and running NetBSD. The machine's presence is said to be transparent to the network. When PacketHound discerns a pattern of traffic that meets the blocking criteria, it returns a reset packet to the requesting machine. The user sees a "Connection reset by host" message."
The company also sells PacketPup, a downloadable program that lets a company monitor bandwidth usage on a network. A similar product called PacketShaper (from Packeteer) analyzes and classifies applications in use on the network in terms of their bandwidth and other behavior.