H.320 protocols define standards for video conferencing equipment that operates over switched digital communication lines. This includes ISDN lines (BRI and PRI) and T-1 lines.
The bandwidth of the connections range from 64 kbps up to a full T-1. Most business grade video conferencing runs at 384 kbps, or 3 ISDN lines.
The H.320 standards are designed for direct connections, not network communications such as over the Internet or a WAN. Since Networks use individually-addressed data packets, video conferencing over a network requires a different protocol - the H.323 standard.
Gateways can be used to connect H.320 standard equipment to H.323 standard equipment. Gateways can be provided by:Both Tandberg and Polycom offer multipoint options which allow H.320 and H.323 equipment to connect.