A number of companies and standards development organizations have, since 2000, been producing products and standards for "time-sensitive networks" to support real-time applications that require a) zero packet loss due to buffer congestion, b) extremely low packet loss due to equipment failure, and c) guaranteed upper bounds on end-to-end latency. Often, a robust capability for time synchronization to less than 1 μs is also required. These networks consist of specially-featured bridges that are interconnected using standard Ethernet links with standard MAC/PHY layers. Since 2012, this technology has advanced to the use of routers, as well as bridges, and features of interest to time-sensitive networks have been added to both Ethernet and wireless standards.