Network Router User Manual

Node Node
...
Node Node
...
78 kbps LON 78 kbps LON
Ethernet
Remote
Monitoring
Configuration
LON/WiFi
Routers
Optional
WiFi to
Ethernet
Bridge
Ad Hoc 802.11b WiFi Channel
Node Node
...
78 kbps LON
Internet
Fig.1.7: Example WiFi Ad Hoc Network
1.4.3. Roaming Connections
Finally, LON to IP gateways may be connected to specialized IP applications instead of to other
gateways. Connecting an IP application to a GRouter device provides these specialized
applications with roaming capabilities which would be dicult if these applications were required
to be directly connected to the 709.1 network (e.g., GadgetAnalyzer, LonMaker-3, etc.). An
example of how several GRouter devices can be interconnected to support an IP backbone for
several LON networks is show in Figure 2.5.
1.5. IP Addressing Modes
e GRouter device uses one of two forms of IP addressing: unicast and multicast. Multicast
currently only works when in manual mode.
e advantage of multicast is that for networks with multiple Gateways (especially in ood
mode), multicast may be more ecient. e disadvantage of multicast is that some internet
routers do not support it. Multicast mode can reduce the IP trac relative to unicast when there
are a large number of 852 devices in the channel. Up to 255 devices per IP domain are supported
with multicast. Some older IP routers do not support multicast and therefore you will not be able
to route 852 packets across a unicast only router with multicast addressing. IP router support for
-12-