48.1 Introduction

Nam is a Tcl/TK based animation tool for viewing network simulation traces and real world packet tracedata. The design theory behind nam was to create an animator that is able to read large animation data sets and be extensible enough so that it could be used indifferent network visualization situations. Under this constraint nam was designed to read simple animation event commands from a large trace file. In order to handle large animtion data sets a minimum amount of information is kept in memory. Event commands are kept in the file and reread from the file whenever necessary.

The first step to use nam is to produce the trace file. The trace file contains topology information, e.g., nodes, links, as well as packet traces. The detailed format is described in the section 49.1. Usually, the trace file is generated by ns. During an ns simulation, user can produce topology configurations, layout information, and packet traces using tracing events in ns. However any application can generate a nam trace file.

When the trace file is generated, it is ready to be animated by nam. Upon startup, nam will read the tracefile, create topology, pop up a window, do layout if necessary, and then pause at time 0. Through its user interface, nam provides control over many aspects of animation. These functionalities will be described in detail in the USER INTERFACE section.

There are bugs in nam however each successive has become much more stable than the previous one. Please mail [email protected] if you encounter any bugs, or have suggestions for addiotional desired functionality.