Diagrams that use the Specification and Description Language (SDL) show
protocol control for circuit-switched basic calls.
If you haven't already done so, first download the
version of RFFlow. It will allow you to open any chart and make
Once RFFlow is installed, you can open the above chart in RFFlow by clicking
From there you can zoom in, edit, and print this sample chart. It is often
easier to modify an existing chart than to draw it from scratch.
To draw this chart without downloading it, run RFFlow and click on the More
button, scroll almost to the end of the list and click the SDL Objects
then click the Add Stencil