Feature Overview - Nokia ESB26 User Manual

14.
topology for frames classified as belonging to VLANs that are mapped to the MSTI by the
MST Configuration Table used by the MST Bridges of each MST Region. The IST is
numbered 0, and the MSTIs are numbered 1, 2, 3, and so on. Each MSTI is local to the MST
region and is independent of MSTIs in the other regions, even if the MST regions are
interconnected.

Feature Overview

Definitions and Acronyms
Table 14-1 defines terms that are used in this document and lists their acronyms as specified
in the IEEE 802.1s standard.
Table 14-1 Definitions and Acronyms of Terms
T e r m
Boundary Port
Common Spanning
Tree
Common and
Internal Spanning
Tree
Internal Spanning
Tree
Multiple Spanning
Tree Instance
MST Configuration
Table
MST Bridge
MST Configuration
Identifier
MN700004 Rev 01
Multiple Spanning Tree Protocol (MSTP)
A c r o n y m D e f i n i t i o n
-- A Bridge Port attaching an MST Bridge to a LAN that is
in another region.
CST The single Spanning Tree calculated by STP and RSTP,
and by MSTP to connect MST Regions.
CIST A collection of the ISTs in each MST region, and the
common spanning tree (CST) that interconnects the
MST regions.
The CIST is calculated by MSTP to ensure that all LANs
in the Bridged Local Area Network are simply and fully
connected.
IST The connectivity provided by the CIST within a given
MST Region.
The IST is the first MSTI in the region, numbered as
MSTI0, and it exists by default and cannot be removed.
All other MST instances are numbered from 1 to 15.
MSTI One of a number of Spanning Trees calculated by MSTP
within an MST Region. The MSTI is defined per VLAN
group, and is designed to provide a simply and fully
connected active topology for frames classified as
belonging to VLANs that are mapped to the MSTI by the
MST Configuration Table that is used by the MST
Bridges of that MST Region.
-- A configurable table that allocates each and every
possible VLAN to the Common Spanning Tree or a
specific Multiple Spanning Tree Instance.
-- A Bridge capable of supporting the CST, and one or
more
classified in any given VLAN to the CST or a given MSTI.
MCID A name for, revision level, and a summary of a given
allocation of VLANs to Spanning Trees.
NOTE—Each
Configuration Table and Configuration Identifier.
140
MSTIs, and of selectively
MST Bridge
mapping frames
uses a single MST