CCNA Cisco Certified Network Associate Study Guide - FTP Server

Glossary 705
sliding window The method of flow control used by TCP, as well as several
Data-Link layer protocols. This method places a buffer between the
receiving application and the network data flow. The “window” available
for accepting data is the size of the buffer minus the amount of data already
there. This window increases in size as the application reads data from it and
decreases as new data is sent. The receiver sends the transmitter announcements
of the current window size, and it may stop accepting data until the
window increases above a certain threshold.
SLIP Serial Line Internet Protocol: An industry standard serial encapsulation
for point-to-point connections that supports only a single routed protocol,
TCP/IP. SLIP is the predecessor to PPP. See also: PPP.
SMDS Switched Multimegabit Data Service: A packet-switched, datagrambased
WAN networking technology offered by telephone companies that
provides high speed.
SMTP Simple Mail Transfer Protocol: A protocol used on the Internet to
provide electronic mail services.
SNA System Network Architecture: A complex, feature-rich, network
architecture similar to the OSI reference model but with several variations;
created by IBM in the 1970s and essentially composed of seven layers.
SNAP Subnetwork Access Protocol: SNAP is a frame used in Ethernet,
Token Ring, and FDDI LANs. Data transfer, connection management, and
QoS selection are three primary functions executed by the SNAP frame.
socket 1) A software structure that operates within a network device as a
destination point for communications. 2) In AppleTalk networks, an entity
at a specific location within a node; AppleTalk sockets are conceptually similar
to TCP/IP ports.
SONET Synchronous Optical Network: The ANSI standard for synchronous
transmission on fiber-optic media, developed at Bell Labs. It specifies a
base signal rate of 51.84Mbps and a set of multiples of that rate, known as
Optical Carrier levels, up to 2.5Gbps.
SP Switch Processor: Also known as a ciscoBus controller, it is a
Cisco 7000 series processor module acting as governing agent for all
CxBus activities.