User's Manual

ME BreadCrumb User Guide Rajant Corporation
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4.0 DEPLOYING THE BREADCRUMB WIRELESS LAN
4.1 OVERVIEW OF BCWL DEPLOYMENT
There are many factors which need to be taken into account when deploying the BreadCrumb Wireless LAN.
Section 2.2 details some of the most commonly occurring environmental factors that will have a major impact on
the performance of the BCWL. Section 2.3 details two common BCWL deployment configurations. Section 3.4
details guidelines and methodology needed to follow when deploying the BCWL.
4.2 DEPLOYMENT CONSIDERATIONS
Commonly occurring environmental factors have a significant impact on performance and behavior of the
BreadCrumb wireless LAN. Line-of-Sight obstructions, distance, weather, and device placement should all be
considered when deploying a wireless LAN.
The IEEE 802.11b/g wireless standard ‘gracefully degrades’ as distance increases between nodes or as
interference becomes present. This will be apparent by a data rate reduction between nodes.
The goal in planning and deploying a BreadCrumb wireless LAN is to maximize data transfer rate between
devices. The data rate can be maximized by taking into consideration all of the contributing factors that affect
data throughput.
4.2.1 ADDRESSING
When routing to another network or when using its own embedded DHCP servers, the BreadCrumb Wireless
Network requires that wireless devices use IPv4 addresses in the Class A network 10.0.0.0/8 (that is, any address
that begins with ‘10.’). If you are not connected to another network, or if you are bridging to one rather than
routing to it, your wireless client devices may have any address whatsoever.
Important: Any devices running the BCAdmin management application must have an address in the 10.0.0.0/8
range. This may be in addition to other addresses the devices may have configured.
4.2.1.1 BREADCRUMB DEVICE ADDRESSES
Each BreadCrumb radio has one IPv4 address in the Class A network 10.0.0.0/8. These addresses are
assigned during manufacturing and cannot be changed in the field. Rajant ensures during manufacturing
that these addresses are not duplicated between any two BreadCrumb devices. Addresses assigned to
BreadCrumb devices can be viewed using BCAdmin.
4.2.1.2 DHCP
Each BreadCrumb device includes an embedded DHCP server. You may safely enable the DHCP
servers of multiple BreadCrumb devices simultaneously, and it is in fact the most common case that all
BreadCrumb devices in a BCWN run DHCP servers. Address conflicts among DHCP clients are
prevented by using the unique BreadCrumb device addresses assigned at the factory as a base.
A BreadCrumb device determines its DHCP range as follows:
1. Start with the first three bytes of the first radio’s IPv4 address.
Add a low-byte range of 10 to 210.