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Glossary

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SAINT

Synergy Advanced Interface and Network

Termination: The SAINT handles Ethernet switching
on the Catalyst 5000 platform, and it also handles ISL
encapsulation.

SAMBA ASIC

ASIC located on line modules and the

Supervisor modules. On the line cards, this chip is
responsible for broadcast suppression, based on
thresholds established by the administrator. This
ASIC also maintains statistics on packets.

sampling rate

The rate at which samples of a spe-

cific waveform amplitude are collected within a spec-
ified period of time.

SAP

(1) Service Access Point: A field specified by

IEEE 802.2 that is part of an address specification. (2)
Service Advertising Protocol: The Novell NetWare
protocol that supplies a way to inform network clients
of resources and services availability on network,
using routers and servers. See also: IPX.

SCR

Sustainable Cell Rate: An ATM Forum param-

eter used for traffic management, it is the long-term
average cell rate for VBR connections that can be
transmitted.

SDLC

Synchronous Data Link Control: A protocol

used in SNA Data-Link layer communications. SDLC
is a bit-oriented, full-duplex serial protocol that is the
basis for several similar protocols, including HDLC
and LAPB. See also: HDLC and LAPB.

secondary nodes

Nodes as designated by the

SDLC protocol. Secondary nodes talk only to the
primary node when they fulfill two requirements.
First, they have permission from the primary node;
second, they have data to transmit.

seed device

A root device specified in a NMS con-

figuration. From this device the network discovery
begins. The seed device's neighbors are discovered and
the continuing process spreads out starting at the seed
device.

seed router

In an AppleTalk network, the router

that is equipped with the network number or cable
range in its port descriptor. The seed router specifies
the network number or cable range for other routers
in that network section and answers to configuration
requests from nonseed routers on its connected
AppleTalk network, permitting those routers to

affirm or modify their configurations accordingly.
Every AppleTalk network needs at least one seed
router physically connected to each network
segment.

sequenced data transfer

This is the process of

assigning sequence numbers to every PDU that leaves
a host so that it may be resequenced once all of the
PDUs in a transmission reach the destination host.

server

Hardware and software that provide net-

work services to clients.

set-based

Set-based routers and switches use the

set

command to configure devices. Cisco is moving

away from set-based commands and is using the Com-
mand-Line Interface (CLI) on all new devices.

Session layer

Layer 5 of the OSI reference model,

responsible for creating, managing, and terminating
sessions between applications and overseeing data
exchange between Presentation layer entities. See also:
Application layer, Data-Link layer, Network layer,
Physical layer, Presentation layer, and Transport
layer.

setup mode

Mode that a router will enter if no con-

figuration is found in nonvolatile RAM when the
router boots. Allows the administrator to configure a
router step-by-step. Not as robust or flexible as the
Command-Line Interface.

super frame: A super frame (also called a D4

frame) consists of 12 frames with 192 bits each, and
the 193rd bit providing other functions including
error checking. SF is frequently used on T1 circuits. A
newer version of the technology is Extended Super
Frame (ESF), which uses 24 frames. See also: ESF.

signaling packet

An informational packet created

by an ATM-connected mechanism that wants to
establish connection with another such mechanism.
The packet contains the QoS parameters needed for
connection and the ATM NSAP address of the end-
point. The endpoint responds with a message of accep-
tance if it is able to support the desired QoS, and the
connection is established. See also: QoS.

silicon switching

A type of high-speed switching

used in Cisco 7000 series routers, based on the use of
a separate processor (the Silicon Switch Processor, or
SSP). See also: SSE.

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