22.1.7 Miscellaneous Trace Events

There are other trace events in addition to the formats described above:

Annotation

This event is represented by event type ``v''. It is used for generic annotation:

v -t <time> <TCL script string>

Notice that this event is very generic, in that it may include an arbitrary tcl script to be executed at a given time, as long as it is in one line (no more than 256 characters). There may be white spaces in the string. The order of flag and the string is important.

Here is an example of this event:

v -t 4 sim_annotation 4 3 node 0 added one mark

This line calls a special tcl function sim_annotation in nam, which inserts the given string node 0 added one mark into nam's annotation pane.

Color

Nam allows one to associate color names with integers. This is very useful in coloring packets, where flow id of a packet is used to color the packet using the corresponding color:

c -t <time> -i <color id> -n <color name>

Notice the color name should be one of the names listed in color database in X11 (/usr/X11/lib/rgb.txt).

Version

The following line define the nam version as required to visualize the given trace:

V -t <time> -v <version> -a <attr>

Normally there is only one version string in a given tracefile, and it is usually the first line of the file.

Hierarchy

Hierarchical address information is defined by:

A -t time -n levels -o address-space size -c mcastshift -a mcastmask -h nth level -m mask in nth level -s shift in nth level This trace gives the details of hierarchy, if hierarchical addressing is being used for simulation. Flag -n <levels> indicate the total number of hierarchical tiers, which is 1 for flat addressing, 2 for a 2-level hierarchy etc. Flag -o <address space size> denotes the total number of bits used for addressing. Flag -h <nth level> specifies the level of the address hierarchy. Flag -m <mask> and -s <shift> describes the address mask and the bit shift of a given level in the address hierarchy, respectively. Here is an example of a trace for topology with 3 level hierachy:

A -t * -n 3 -p 0 -o 0xffffffff -c 31 -a 1
A -t * -h 1 -m 1023 -s 22
A -t * -h 2 -m 2047 -s 11
A -t * -h 3 -m 2047 -s 0

The functions that implement the different nam trace formats described above may be found in the following files: /trace.cc, /trace.h, /tcl/lib/ns-namsupp.tcl.