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	Secam
	A colour television system developed by the French and used in the former USSR. Secam operates with 625 lines per picture frame and 50 cycles per second. It is incompatible with the European PAL system or the U.S. NTSC system.
	Serial Host
	A device, such as a videoconferencing codec, that is connected to a serial host port communicating over a point-to-point link. To a serial host, the MAX appears to be a cable or DCE (Data Communications Equipment).
	Serial Host Port
	The V.35, RS-499, or X.21 port on the MAX.
	Serial Host Port Module
	A module on the MAX that connects to a serial host through its serial host port.
	Standard compression algorithm
	An algorithm convention for compression of a video signal. Adherence to standards allows communication among a wide variety of videoconferencing systems, though not with the same clarity as two similar systems using a proprietary algorithm. H.320 /H.323 are the most widely accepted standards in use today.
	Switched 56
	A dial-up network-based service providing a data channel operating at a rate of 56 kbps. Also a type of network access line, used to provide access to switched 56 network services.
	SDSAF (Switched Digital Services Applications Forum)
	A consortium of equipment vendors, service vendors, and users, with the goal of advancing the state of switched digital services.
	SVC (Switched Virtual Circuit)
	A path over a packet-switched network that appears to be a dedicated circuit, but in fact the connection only stays up as long as needed, and then ends.
	Synchronization
	In serial data transmission, a method of ensuring that the receiving end can recognize characters in the order in which the transmitting end sent them, and can know where one character ends and the next begins. Without synchronization, the receiving end would perceive data simply as a series of binary digits with no relation to one another. Synchronous communication relies on a clocking mechanism to synchronize the signals between the sending and receiving machines.