A tool to visualize network connections

Currently I'm planning on using dot and it's family.

I want to know if开发者_开发技巧 there is something more appropriate?

I'll need to show several levels, card and network connection(input and output):

----------
|IOIOIOIO|
--|-------
  \\
---|------
|IOIOIOIO|
----------

If you don't need the automatic layout graphviz offers, you may use ditaa to create nice diagrams. There's an online version you may take a look at for a quick test.