We put in about 5-6 DD Mode “repeaters”/nodes in Minneapolis/St Paul to support database application access at scale for the Medtronic Twin Cities Marathon in around 2007.? It worked well.? The range was excellent and web type apps ran fine.? The point to point nature of the protocol was a limitation.? We had multiple stations on ID-1s via Icom “repeater” nodes that needed to reach our data trailer.? KD8GBL came up with an idea to use DNAT- and use multiple /24 addresses blocks- so four ID-1s could reach one ID-1 on the database.? ?DNAT ran on a Linux box on the Ethernet on the “repeater.” We had up to three uplink ID-1s in the data trailer, each feeding an Icom ?“repeater” on a building rooftop.? (Having the database and “repeaters” co located was not possible).? ?

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We found the system reliable and interference free.? In no way a failure.?

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The protocol needs an update to allow meshing.? We did not find the linking feature of D-Star DD (via the Internet, callsign routing etc.) to be useful and bypassed it.?

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DD Mode was complex and widely misunderstood as an Internet /ISP solution and does not support full duplex well so was not useful for video or VoIP.? The ID-1 is semi mysterious and acts like an Ethernet bridge.? But for web disaster database apps it is still in use as our backup.?

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We routinely got 10 mile range on an Omni antenna DD-1 to an Icom node

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Erik NY9D?? www.14567.org

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