For people who are in VoIP business.

Here is the link
http://armkb.com/qnmodeler

Here is description

Purpose
When you need to explain a network topology to someone or understand someone's topology you may use this online tool to build and share diagram of topology.

Benefits

• No need to install any 3rd party software on your hard drive
• Completely free
• Can store and load diagrams from server
• Multi language support
• As small as ~200kb flash file
• Multi platform and supports all browsers that supports flash
• Already got almost any tool for building robust IP telephony diagrams

All you have to do, create diagram, export and give to your colleague diagram name.

Modeler is highly configurable and if someone would like to have different set of items or have any commercial offer may contact me.