The technology in this field enables us to use the Internet or intranet line as a video transmission method. DSL and T-1 are for the Internet connection and LAN (or WAN) is for intranet.

DSL

DSL, Digital Subscriber Line, is commercialized with the speeds from 144 Kbps to 1.1 Mbps. (More than 1.5 Mbps speed is called T-1). To connect a web camera to a DSL, you need a router with RJ45 jack. The router is usually provided by DSL supplier. If you need to connect multiple web cameras, you should have a hub which has multiple RJ45 jacks and which is to be connected to the router. You will have static and public IP address(es) (provided by the DSL supplier) to assign to the web camera(s). This IP address will work as a web site address on the Internet.

At the site of web camera, business grade SDSL(Symmetric DSL) is recommended. SDSL has same upstream and downstream bandwidth, while other DSL (IDSL or ADSL) has larger downstream bandwidth than upstream. As web camera's video data should be uploaded to the Internet, a SDSL is much better for the web camera. But to see the pictures from the camera, that is to download it, a residential DSL or even Cable TV line will work fine. (See more details about the bandwidth and the speed of a web camera)

LAN

LAN, Local Area Network or WAN, Wide Area Network has intranet network in a limited area or organization and has a lot of computers connected to the network. Web camera servers, as like other computers, can be connected to LAN or WAN so that other computers can share the video data. Web camera servers can be connected to LAN or WAN through RJ45 jacks.