The infranet is a proposed universal, public, packet-switched supplement to the Internet for businesses and high-demand private users that would provide guaranteed security, reliability, and quality of service (QoS). The Infranet Initiative, a group dedicated to the development and deployment of the "next-generation business-class IP network", says the infranet will be ideal for applications such as utility computing, multi-provider VPNs, and inter-enterprise peer-to-peer collaboration that are too demanding to run reliably over the Internet.
Although ISPs proposed a similar network based on frame relay and ATM (asynchronous transfer mode) in the early 1990s, neither businesses nor the technology were ready for the change. Because ATM and frame relay are connection-oriented, they maintain a single connection, with a single path of transmission, for a communication; as a consequence, it is difficult to ensure quality of service. To overcome this difficulty, the infranet would use Multiprotocol Label Switching (MPLS), which transmits data over whatever routes necessary to ensure the desired level of service and provide faster transmission overall.
The term infranet was originally coined to refer to the infrastructure of a network. For the Internet, for example, the infranet is that portion of the network on which data packets are exchanged using Internet protocols. It can also be said to include private network infrastructures that use the Internet set of protocols, TCP/IP, whether or not these interconnect with the public Internet.