Technical data

socket pair
The client IP address and port number, and the server IP address and port number
that uniquely identify a TCP connection.
source
The IP header field that contains the IP address of the datagram’s point of origin.
source port
A 2-octet value in the TCP or UDP header field that identifies the upper-level
application or protocol associated with the data in the segment.
spanning tree
A logical arrangement created by bridges in an extended LAN in which all LANs
are connected and there are no loops.
split horizon
When a router (or group of routers work together) accepts routing information from
multiple external networks, but does not pass on information learned from one
externalnetworktoothers.Thisisanattempttopreventfalseroutestoanetwork
from being propagated because of gossip or counting to infinity.
splitting
The process of mapping one transport connection to several network connections.
stateless
A characteristic of a server designed to simplify crash recovery after a server
crashes and reboots. The server does not keep track of the status of ongoing client
interactions. Servers that do not keep track of client status are called stateless
servers.
static routing
A routing method by which a system manager manually adds routes to the kernel’s
routing table. This method is generally used on small networks. On Open VMS
systems, you use the SET ROUTE command to add static routes and on UNIX
systems, you use the
route
command.
step
To change the time of a clock to the correct time with no intermediate adjustments.
Compare with slew.
stratum
The distance a host running the NTP time daemon is from an external source of
Coordinated Universal Time (UTC). A stratum 1 server has direct access to an
external source of UTC, such as a radio clock synchronized to a standard time
signal broadcast. In general, a stratum n server is n - 1 network hops away from a
stratum 1 server. For example, a stratum 4 server is 3 hops away from a stratum 1
server. Also, a stratum n server is at a higher stratum than a stratum n -1server.
For example, a stratum 3 server is at a higher stratum than a stratum 2 server,
and at a lower stratum than a stratum 4 server. See also time daemon.
stream-oriented
The type of transport service that allows its client to send data in a continuous
stream; guarantees that all data will be delivered to the other end in the same
order as sent and without duplicates. Also known as a reliable transport service.
Structure of Management Information (SMI)
The rules used to define the objects that can be accessed by means of a network
management protocol. See also Management Information Base.
Glossary–43