SGlossary
B-66 Centillion 1200N ATM Switch User Manual
NTP 297-8103-903
S
SA
Source Address: The address from which the message or data originated.
SA
Source MAC Address: A six octet value uniquely identifying an end point and
which is sent in an IEEE LAN frame header to indicate source of frame.
SAAL
Signaling ATM Adaptation Layer: This resides between the ATM layer and the
Q.2931 function. The SAAL provides reliable transport of Q.2931 messages
between Q.2931 entities (e.g., ATM switch and host) over the ATM layer; two
sublayers: common part and service specific part.
SAP
Service Access Point: A SAP is used for the following purposes:
• When the application initiates an outgoing call to a remote ATM device, a
destination_SAP specifies the A TM addre ss of the remot e device, plus further
addressing that identifies the target software enti ty within the remote device.
• When the application prepares to respond to incoming calls from remote ATM
devices, a local_SAP specifies the ATM address of the device housing the
application, plus further addressing that identifies the application within the
local device. There are several groups of SAPs that are specified as valid for
Native ATM Services.
SAR
Segmentation and Reassembly: Method of breaking up arbitrarily sized packets.
SC
Subscriber loop system optical fiber Connector: It’s a system that allows one pair
of wires, that would normally provide one phone line, to carry multiple
conversations. Various models are available, with capacity ranging from 2 to 96
lines. A SC or (SLCC) is used between phone company central offices and areas
where there are too many customers for the cable that is in place. It’s much less
expensive to install SLCCs than new cable, but the SLCC provides lower-than-
normal line voltage, which may cause some phones to malfunction.