- Cisco ONS 15454 Manual

D-11
Cisco ONS 15454 Installation and Operations Guide
November 2001
Appendix D Glossary
RMON
Remote Network Monitoring. Allows network operators to monitor the health of the network with a
Network Management System (NMS). RMON watches several variables, such as Ethernet collisions,
and triggers an event when a variable crosses a threshold in the specified time interval.
S
SNMP
Simple Network Management Protocol. Network management protocol used almost exclusively in
TCP/IP networks. SNMP monitors and controls network devices and manages configurations, statistics
collection, performance, and security.
SNTP
Simple Network Time Protocol. Using an SNTP server ensures that all ONS 15454 network nodes use
the same date and time reference. The server synchronizes alarm timing during power outages or
software upgrades.
Soft reset
A soft reset reloads the operating system, application software, etc., and reboots the card. It does not
initialize the ONS 15454 ASIC hardware.
SONET
Synchronous Optical Network. High-speed synchronous network specification developed by Telcordia
Technologies, Inc. and designed to run on optical fiber. STS-1 is the basic building block of SONET.
Approved as an international standard in 1988.
Source
The endpoint where traffic enters an ONS 15454 network. Endpoints can be a path (STS or STS/VT for
optical card endpoints), port (for electrical circuits, such as DS1, VT, DS3, STS), or card (for circuits on
DS1 and Ethernet cards).
Spanning tree
Loop-free subset of a network topology. See also STA and STP.
SPE
Synchronous Payload Envelope. A SONET term describing the envelope that carries the user data or
payload.
SSM
Sync Status Messaging. A SONET protocol that communicates information about the quality of the
timing source using the S1 byte of the line overhead.
STA
Spanning-Tree Algorithm. An algorithm used by the spanning tree protocol to create a spanning tree.
See also Spanning tree and STP.