Glossary
GL-25
Cisco 6260 Hardware Installation Guide
OL-2365-02
SLIP
Serial Line Internet Protocol. A standard protocols for point-to-point serial connections using a
variation of TCP/IP. This protocol is the predecessor of PPP. See
PPP
and
TCP
.
slot
A numbered location within a chassis, which is capable of housing a card or module.
SMF
single-mode fiber. Fiber-optic cabling with a narrow core that allows light to enter only at a single
angle. Such cabling has higher bandwidth than multimode fiber, but requires a light source with a
narrow spectral width (for example, a laser). See also
MMF
.
SNMP
Simple Network Management Protocol. The network management protocol of choice for
TCP/IP-based internets. SNMP provides a means to monitor and control network devices, and to
manage configurations, statistics collection, performance, and security.
SNR
signal-to-noise ratio. The usable signal being transmitted divided by the noise or undesired signal.
SNR is a measure of transmission quality.
SONET
Synchronous Optical Network. A standard format for transporting a wide range of digital
communications services over optical fiber. SONET is characterized by standard line rates, optical
interfaces, and signal formats.
source address
Address of a network device that sends data. See also
destination
address
.
star topology
A method of connecting devices in which end points on a network are connected to a common central
switch by point-to-point links. Compare with
bus topology
,
daisy-chain topology
,
ring topology
, and
tree topology
.
STM-1
Synchronous Transfer Module 1. Synchronous Digital Hierarchy standard for transmission over
OC-3c optical fiber at 155.52 Mbps.
STS-3c
Synchronous Transport Signal level 3, concatenated. SONET format that specifies the frame structure
for the 155.52 Mbps-lines used to carry ATM cells. See also
SONET
.
STU-C
See
xTU-C
.
STU-R
See
xTU-R
.
subinterface
One of a number of virtual interfaces on a single physical interface.
subnet
For routing purposes, IP networks can be divided into logical subnets by means of a subnet mask.
Values below those of the mask are valid addresses on the subnet.
subnet address
Portion of an IP address that is specified as the subnetwork by the subnet mask.
subnet mask
The 32-bit address mask used in IP to indicate the bits of an IP address that are being used for the
subnet address.
subrack discovery
The process by which a DSLAM node automatically searches through the interfaces and ports within
that DSLAM and discovers the components that are present within that DSLAM.
subscriber
A logical entity with attributes identifying the customer that is receiving service on a particular port.
subtended
configuration
Services and aggregates the data from one or more chassis into a subtending host chassis requiring
only one connection to the outside network. This reduces the number of ATM edge-switch ports
necessary to terminate multiple chassis.