Setup guide

Glossary
GL-12
Cisco 6400 Software Setup Guide
OL-1183-04
S
SAR segmentation and reassembly.
SCM
Service Connection Manager.
SCR sustainable cell rate. Parameter defined by the ATM Forum for ATM traffic management. For VBR
connections, SCR determines the long-term average cell rate that can be transmitted. See also VBR.
SDH Synchronous Digital Hierarchy. European standard that defines a set of rate and format standards that
are transmitted using optical signals over fiber. SDH is similar to SONET, with a basic SDH rate of
155.52 Mbps, designated at STM-1. See also SONET and STM-1.
SIMM
single in-line memory module. Used for Flash internal memory in the Cisco 6400.
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). Also called monomode fiber. See also multimode fiber.
SNAP Subnetwork Access Protocol. Internet protocol that operates between a network entity in the
subnetwork and a network entity in the end system. SNAP specifies a standard method of encapsulating
IP datagrams and ARP messages on IEEE networks.
SNMP
Simple Network Management Protocol. Network management protocol used almost exclusively in
TCP/IP networks. SNMP provides a means to monitor and control network devices, and to manage
configurations, statistics collection, performance, and security.
soft PVC A PVC-SVC hybrid in which only the two terminating virtual connection links (VCLs) at either end
are permanent and the rest of the VCLs are switched (SVC). Like the PVC, a soft PVC is permanent
and the called party cannot drop the connection. Like the SVC, a soft PVC is automatically rerouted if
a switch or link in the path fails.
SONET Synchronous Optical Network. High-speed (up to 2.5 Gbps) synchronous network specification
developed by Bellcore and designed to run on optical fiber. STS-1 is the basic building block of
SONET. Approved as an international standard in 1988. See also SDH, STS-1, and STS-3c.
SSD
The Service Selection Dashboard (SSD) server is a customizable Web-based application that works
with the Cisco SSG to allow end customers to log on to and disconnect from proxy and passthrough
services through a standard Web browser. After the customer logs in to the service provider's network,
an HTML Dashboard is populated with the services authorized for that user.
SSG Service Selection Gateway. The Cisco SSG offers service providers a means for menu-based service
selection. End users can select services from the Dashboard menu, and the Cisco SSG will set up and
tear down proxy and passthrough network connections based on a user's selection. The Cisco SSG will
account for the services selected so that service providers can bill for individual services.
Stratum 3 A precision timing reference that provides a free-run accuracy of +/- 4.6 PPM (parts per million),
pull-in capability of 4.6 PPM, and holdover stability of less than 255 slips during first day. Thorough
descriptions can be found in ANSI T1.101-1994 and the Bellcore document GR-1244-CORE.
STS-1
Synchronous Transport Signal level 1. Basic building block signal of SONET, operating at 51.84 Mbps.
Faster SONET rates are defined as STS-n, where n is a multiple of 51.84 Mbps. See also SONET.