*6.1.3 ADSL Internet access networking program*

This networking scheme refers to client network or equipment access to the Internet through asymmetric digital subscriber line (ADSL) and the use of the Internet to form an interconnected network. This type of networking can provide up to 3.5 Mbps uplink and up to 24 Mbps downlink, and the cost of access is usually between several hundred and several thousand dollars per year in various provinces and cities. Although the cost of this solution is lower than that of private network and fiber optic Internet access methods, the actual available bandwidth drops when public network resources are insufficient, and upstream and downstream bandwidths are inconsistent because the data streams pass through the public network and share the public network bandwidth with the other user data streams. Therefore, the bandwidth stability is poor with this networking method, which may adversely affect two-way audio and video interaction applications with high bandwidth stability requirements, such as non-smooth video. Nevertheless, the networking scheme still has the advantages of easy networking and low cost and is suitable for building a telemedicine system using software video among hospitals below the county level. Some of the hospitals' self-built teleconsultation systems using software video partially adopt this networking method, which is one of the most common Internet access methods for small institutions and individual users.
