ZTE ZTE Verizon ZTE Verizon Latency and packet loss is such requirement that must be achieved according to the Service Level Agreement (SLA) / Network Performance Objective (NPO) between customers and service providers. Latency and packet loss can be associated with different service level. The user may select a private line provider based on the ability to meet a latency and loss SLA. The key driver for latency and loss is stock/commodity trading applications that use data base mirroring. A few milli seconds and packet loss can impact a transaction. Financial or trading companies are very focused on end-to-end private pipe line latency optimizations that improve things 2-3 ms. Latency/loss and associated SLA is one of the key parameters that these "high value" customers use to select a private pipe line provider. Other key applications like video gaming, conferencing and storage area networks require stringent latency, loss and bandwidth. This document describes requirements to communicate latency and packet loss as a traffic engineering performance metric in today's network which is consisting of potentially multiple layers of packet transport network and optical transport network in order to meet the latency/loss SLA between service provider and his customers.