There are two major ways to provide Internet telephony. One is over a public network, such as the Internet, rather than over traditional phone lines. Voice is converted into digital bits, which are then stuffed into Internet packets (IPs), like a virtual envelope, and sent through the Internet. Because each IP has its own stamp, or header, they can travel over any number of routes before arriving at their final destination where they are reassembled. But the Internet itself is far too unstable. Traffic gets congested at different times around the world due to the time differences. Lack of bandwidth in some countries aggravates the problem. What Mr Chen envisions, instead, is another scheme, usually called 'voice over IP'. Here, the same IPs do not necessarily travel through the Internet. Instead, they may travel through a corporate leased line, an intranet or a virtual private network (VPN), all so expensive that only big companies have them. 'We see voice over IP as a technology that is moving very fast. I'm not saying that IP will be everything, but it will be ubiquitous,' Mr Chen said. In Hong Kong, telecoms companies and Internet service providers can offer voice over IP only to companies, who can let only employees call other employees worldwide. Consumers must wait until after January 2000, when it becomes legal.