IETF RFC 2678 PDF

Introduction

Connectivity is the basic stuff from which the Internet is made. Therefore, metrics determining whether pairs of hosts (IP addresses) can reach each other must form the base of a measurement suite. We define several such metrics, some of which serve mainly as building blocks for the others.

This memo defines a series of metrics for connectivity between a pair of Internet hosts. It builds on notions introduced and discussed in RFC 2330, the IPPM framework document. The reader is assumed to be familiar with that document.