If it could not be compressed for transmission, links would be limited to broadband radio transmissions and broadband fiber optic cable. Until recently it was large and expensive. A second board provides the communications interface with POTs, ISDN, and ether net connection or other transmission mediums. At present there are many proprietary systems on LANs which can only communicate with other systems from the same supplier. As CPU chips get faster, they are taking over the hardware functions of compression and decompression with software.
Video quality improves with processor speed.
Many existing LAN based video systems communicate with proprietary protocols. This is because of the recent and evolving nature of standards and because proprietary algorithms provide better audio and video. As a result, even if many existing LAN video systems could connect over public telephone lines to other LANs with video from other manufacturers, most could not share data and applications. Some standards have now been adopted and new ones are evolving to standardize larger segments of the DVC industry. Compliance with and understanding of standards is important in selecting and implementing a DVC system.