Table of Contents
Advertisement
Chapter 10 - Local Mesh
The maximum number of upstream and downstream links that this node can support.
10.3.1.3.3.7 Initial Discovery Time
(Alternate master or slave nodes)
Amount of time that will be taken to discover the best available master node. The goal of this setting
is to delay discovery until all the nodes in the surrounding area have had time to startup, making the
identification of the best master more accurate. If this period is too short, a slave may connect to the
first master it finds, not necessarily the best.
10.3.1.3.3.8 Maximum Links
The maximum number of upstream and downstream links that this node can support.
10.3.1.3.3.9 Promiscuous Mode
(Alternate master or slave nodes)
Although it could be used in other applications, the promiscuous mode is primarily intended to solve
issues specific to local mesh networks aboard trains. The main issue that it addresses is train
configuration changes. When a car is taken out for maintenance and replaced with a new one, the AP
in that new car will not be able to connect to the train's local mesh network because it is configured
with a different mesh ID. This is where the promiscuous mode comes into play. Its goal is to allow a
node to connect to a different mesh when it could not find any available master (alt-master) in its
mesh for a certain, configurable, amount of time.
When a node joins a new mesh, it is considered to be the consequence of a car change (or
replacement of an AP). This event triggers the following actions:
The node's firmware is updated, given that a firmware update URL is configured.
The node's configuration is updated, given that a configuration file URL is configured. This
will consequently change the node's mesh ID to the one found in the configuration file. If
no configuration file URL is provided, the node will immediately proceed with updating its
mesh ID.
An SNMP trap is sent.
NOTE
After completing a configuration or firmware download, a local mesh node will wait an additional 30
seconds before rebooting if a downstream link was established with another node in promiscuous
mode. The purpose of this delay is to give downstream nodes some more time to download their
firmware and configuration, improving the total convergence time of an entire train network after a
master car change.
10.3.1.3.3.10Preserve Master Link Across Reboots
(Alternate master or slave nodes)
182
BreezeMAX Wi² and BreezeACCESS Wi² System Manual
Advertisement
Table of Contents
