Transition Networks, Inc.
S4224 Web User Guide
33595 Rev. C
Page 663 of 669
interpreted by the server. An example of a stateless protocol is HTTP. The protocol provides no means of
storing a user's data between requests. As a work-around, HTTP Servers implement various session
management methods, typically utilizing a unique identifier in a cookie or parameter that allows the server to
track requests originating from the same client. Contrast this with a traditional FTP server that conducts an
interactive session with the user. During the session, a user is provided a means to be authenticated and set
various variables (working directory, transfer mode), all stored on the server as part of the user's state. From
Wikipedia.
STP
S
panning
T
ree
P
rotocol is an OSI layer-2 protocol which ensures a loop free topology for any bridged LAN. The
original STP protocol is now obsolete by RSTP.
Sub-ring
An Ethernet ring which is connected to one or more other Ethernet rings or networks through using a pair of
interconnection nodes. On their own, the sub-ring links do not form a closed loop. A closed connection of traffic
may be formed by the sub-ring links and one or more links that are controlled by another Ethernet ring or
network, between interconnection nodes. From ITU-T Rec.G.8032/Y.1344 (03/2010).
Sub-ring link
A span (e.g., link/port) connecting adjacent sub-ring nodes that is under the control of the Ethernet ring protocol
control process (ERP control process) of the sub-ring. From ITU-T Rec.G.8032/Y.1344 (03/2010).
Subnet Mask (Address Mask)
A bit mask used to identify which bits in an IP address correspond to the network and subnet portions of the
address. Referred to as the 'subnet' mask because the network portion of the address (the network mask) can
be determined by the encoding inherent in an IP address.
Synchronized clocks
Two clocks are synchronized to a specified uncertainty when they have the same epoch and their
measurements of the time of a single event at an arbitrary time differ by no more than that uncertainty.
T
(
T
erminal
A
ccess
C
ontroller
A
ccess
C
ontrol
S
ystem
P
lus) is a networking protocol which provides
access control for routers, network access servers and other networked computing devices via one or more
centralized servers. provides separate authentication, authorization and accounting services.
Tag
An optional field in a frame header. In MEF 26 it is the 4-byte field that, when present in an Ethernet frame,
appears immediately after the Source Address, or another tag in an Ethernet frame header and which consists
of the 2-byte Tag Protocol Identification Field (TPID) which indicates S-Tag or C-Tag, and the 2-byte Tag
Control Information field (TCI) which contains the 3-bit Priority Code Point, and the 12-bit VLAN ID field.
Tag Priority
Tag Priority is a 3-bit field storing the priority level for the 802.1Q frame.
TCP
TCP (Transmission Control Protocol) is a communications protocol that uses the Internet Protocol (IP) to
exchange the messages between computers. The TCP protocol guarantees reliable and in-order delivery of
data from sender to receiver and distinguishes data for multiple connections by concurrent applications (for
example, Web server and e-mail server) running on the same host.
The applications on networked hosts can use TCP to create connections to one another. It is a connection-
oriented protocol, which means that a connection is established and maintained until such time as the message
or messages to be exchanged by the application programs at each end have been exchanged. TCP is
responsible for ensuring that a message is divided into the packets that IP manages and for reassembling the
