TTM's main purpose is to provide standardized metrics for one-way delay and one-way packet loss between measurement devices in a format, which is easily understood by users. One-way measurements are vital, since more and more of Internet routing is becoming asymetrical, i.e. packets use different paths between two nodes depending on the direction of traffic. The TTM project complies with standards that are maintained and developed by the IETF's IP Performance Metrics Working Group (RFC's 2330, 2678 through 2681).