User Guide

NETNode Operations Guide
Commercial in
Confidence
IP Mesh Systems
000-130
R1.8 2015-07-24
Commercial in
Confidence
Page 2-46
NETNodes can also send out an initial RIP v2 general query packet to aid starting up of the
network.
Note: NETNodes do not currently snoop on OSPF packets.
2.17 Spanning Tree Protocol
V5.0 of the software now allows STP/RSTP packets to pass through the system. This allows
external routers to check for IP loops in the network.
Figure 2-19 Spanning Tree Protocol
A packet entering a port of the MESH network is forwarded on to all other ports on the
MESH in the same way as a broadcast packet. A fixed value of 5000000 is added to the
current route path cost for STP/RSTP packets which go across the radio interface. This
allows a router to favour non MESH radio routes when a direct Ethernet path is available.
CAUTION: It is recommended to disable STP in interlink mode. During a master-slave
switch it is possible for an STP packet originating from a particular router port to be sent
back to the same port. This may cause the port to shut down.
2.18 Roaming
Roaming allows a NETNode to move between one MESH network and another. This is very
useful, for example, in city networks where there can be a large number of nodes or
sufficient bandwidth to support the use of multiple frequencies. Another example might be
an airborne environment where an aircraft may be required to join different city MESH’s
located across the country.
Each separate MESH Network is called a ‘zone’. A zone can consist of a single NetNode base
station or a large existing MESH network with multiple connected high point ‘base-station’
nodes.
Roaming currently supports four modes of operation: ‘Off’, ‘Round Robin’, ‘GPS Location’ and
‘External/Manual’. Round Robin hops sequentially between networks; while GPS location uses
a simple path loss model to pick the best network to join. There are advantages and
disadvantages in each method. The External/Manual mode allows control of the zones
through a remote command or by the manual zone button. This allows applications such as