Since your dynamic DNS will always be the same, and as long as your are online, anyone will be able to contact you, whatever your IP address is. They will never need to know it anymore to contact you. For more information about Dynamic DNS, please read the paragraph about my DynSite program on the download page . At the beginning of desktop videoconferencing, the systems from different brands were not all able to communicate with each others. But since then more and more standards have been done and things are more and more smooth.
Protocols Here are some of the standards used in videoconferencing.
For more information please take a look at the DataBeam's primer pages on T.120 and H.323. The OpenH323 Project , open source H.323 stack and more open source stuff for Internet telephony. You can call any phone numbers from your PC either using a conferencing application or an applet on a web page. Some of these services are listed below. 4eCalls FREE web based telephone calls to Ireland, UK, US and Canada.