ALTO Performance Cost Metrics

Cost Metric is a basic concept in Application-Layer Traffic Optimization (ALTO). It is used in both the Cost Map Service and the Endpoint Cost Service. Future extensions to ALTO may also use Cost Metric. Different applications may benefit from different Cost Metrics. For example, a Resource Consumer may prefer Resource Providers that have low delay to the Resource Consumer. However the base ALTO protocol [ALTO] has documented only a single cost metric, i.e., the generic "routingcost" metric (Sec. 14.2 of ALTO base specification [ALTO]). In this document, we proposes a set of Cost Metrics, derived and aggregated from routing protocols with different granularity and scope, such as BGP-LS,OSPF-TE and ISIS-TE, or from end to end traffic management tool. We currently document 11 new Performance Metric to measure network delay, jitter, packet loss, hop count, and bandwidth. The metrics documented in this document provide a relatively comprehensive set of Cost Metrics for ALTO and allow applications to determine "where" to connect based on end to end network performance criteria. Additional Cost Metrics such as financial cost metrics may be documented in other documents.