Introduction

This note is in response to Bill English's Request for Comments: 28.

A "millisecond" clock should be satisfactory for most network measurements. Round-trip message transit times typically should be at least on the order of tens to hundreds of milliseconds. The IMP contains a 16-bit hardware clock which is incremented every 100 microseconds to allow for timing of internal events within the IMP, as for example, during tracing. However, most measurements are made using a 25.6 ms. software clock.