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I have an idea to provide additional radio network connectivity to
the Snohomish County DEM at Paine on 23cm, that would require one or
two fixed 44.x.x.x IP addresses at the DEM, and one at my house
(separate from my MikroTik radio), that would be accessible via the
present 44.24.240.x connection to Paine (and perhaps any other
44.24.240.0/20 address). Both involve the use of two (or more) Icom
ID-1 radios in D-Star DD mode.<br>
<br>
Background: An Icom ID-1 in DD mode acts just like a piece of
Ethernet cable (except that it is half-duplex and limited to a raw
128Kbps speed). No IP address is (or can be) assigned to the
device. Any Ethernet packet reaching the ID-1's Ethernet port
(whatever the content) is simply encapsulated and transmitted if the
radio is in DD-mode. Similarly, any received data (properly
encapsulated by another ID-1) is simply sent out the receiving
radio's Ethernet port. The only radio configuration possible is to
select a 23cm frequency and set the radio into DD-mode. Most of
these actions can either be done by the radio's control head, or via
a USB port "connected" to a Windows PC running Icom's control
software for the ID-1. This prior sentence is important in the
following discussion.<br>
<br>
As an aside, the transmission of an ID-1 can be addressed to and
received by a D-Star DD-mode "repeater" module, routed via the
D-Star network over the Internet to another such "repeater" module
anywhere in the world, and retransmitted over the air to a receiving
ID-1 radio. This mechanism, while perhaps interesting, is not the
subject of this eMail. I only mention it so as to avoid confusion.<br>
<br>
In scenario #1 for the ID-1 that already is installed at the
Snohomish County DEM:<br>
<ol>
<li>The Ethernet port of the ID-1 is directly connected to a
switch at the DEM that is on the 44.24.240.x network. In this
mode, any packets received over-the-air by the ID-1 are injected
into the local 44.24.240.x network, and are routed in exactly
the same manner as from any other device hard-wired to the
44.24.240.x network at the DEM. Further, any Ethernet packets
seen by the ID-1 (whether intended for radio transmission or
not), would be transmitted by the ID-1.</li>
<li>Another ID-1, located (say) at my house would be connected to
a router, which would act as though it were directly connected
to the 44.24.240.x network at the DEM.</li>
</ol>
I don't view the above scenario as a good idea. For one thing, the
indiscriminate transmissions from the DEM of unrelated 44.x.x.x
packets doesn't seem like a good idea. For another, there is no
security. So, that brings me to scenario #2:<br>
<ol>
<li>At the Snohomish County DEM, place a router (or bridge)
between the ID-1 and the 44.24.240.x network.</li>
<li>In this scenario, the ID-1 located at my house would also be
connected to a router that acts as though it were directly
connected to the 44.24.240.x (or any other) network at the DEM.</li>
</ol>
<p>Now, here is the wrinkle (to both scenarios): The ID-1 at the
DEM is currently in VERY LOW utilization, being (as so far as we
know) only able to contact my ID-1 (in either digital data or
voice mode), and the two 23cm D-Star K7LWH repeater modules (one
voice, and presumably one data) in Bellevue. Also, the ID-1 also
supports normal FM voice mode, and is easily able to hit with one
watt (from both the DEM and my house) the KB7CNN 23cm FM repeater
on East Tiger Mountain. So, it would be nice to use the DEM's
ID-1 radio in different modes, as needed, and switch modes or
frequencies REMOTELY as desired. The solution to this the use of
a Digi "Anywhere/5" (or "/2") Ethernet-to-USB box (I have
several). With the installation of Digi drivers on any Windows
PC, these allow a PC anywhere in the world to connect over the
Internet to a Digi box and have access to several remote USB
devices (including any connected USB hubs). In particular, the
USB control port of an ID-1. In fact, this is how I control my
ID-1 at home: this allows me to control the ID-1 from any Windows
PC.<br>
</p>
<p>Hence the desire for a fixed 44.24.240.x IP address for the Digi
box at the DEM, allowing REMOTE control and configuration of the
ID-1 when the Internet is not available. While the Digi box can
be connected to any network at the DEM, it seems most productive
to connect it to the 44.24.240.x network there, allowing remote
configuration and control of the ID-1 in an Internet outage (this
can be disabled by unplugging the ID-1's USB port).
Unfortunately, the Digi USB boxes are only usable from Windows
systems (Digi's remote SERIAL (RS-232) port boxes are supported
not only on Windows from 98 on, but on most variants of Linux
...).<br>
</p>
<p>Yes, this provides a much slower connection to the DEM than the
MikroTik radios, but doesn't have quite the strict line-of-sight
issues that 5cm does, and thus permits some mobile access.<br>
</p>
<p>To Scott Hokaker:<br>
</p>
<p>I am willing to provide a Digi "Anywhere/5" box on permanent loan
(or perhaps donation) to this project. I also have a couple of
consumer-grade routers (Linksys BEFSR41, Netgear WGT624v2) that
are similarly available, if they are suitable.<br>
</p>
<p>Comments welcome!<br>
</p>
<p>-- Dean<br>
</p>
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