GB7CD was the fat repeater connected to the new reflector, soon followed by the HotSpot based GB3WE.

Having GB3WE connected it seems quite clear that to a user connected via RF to GB7CD that users on GB2WE appear as though they were using any Icom repeater. Their call sign, and user message all get routed through, even in the Dplus log of GB7CD there is no noticeable difference.

I don’t see how any objection could be based on little more than Myth that has prevented GB3WE and other node adapters being connected to the other UK Reflectors.

The MidStar D-Star repeaters are to start using port B on Ref21, where they also intend to make use of node adapter based repeaters, to complement their current Icom based one.   Â

I understand there has been a lot of interest in exactly where Reflector 21 is located and the kind of hardware and network connections used. Here is the low down, its located in London at a Blueconnex Data centre
The hardware is a Quad Core Xeon, 4GB of Ram, Mirrored disks The network connectivity is provided currently by a Duplex 100Mbps port, which has the capacity to be a 1Gbps port, but I’ve turned it down on the switch, as I doubt we need 1Gbps.

Internet Connectivity to most of the UK is via LINX which should provide a decent low hop count to ADSL lines which so many reflectors use. From other systems connected in different Datacentres around London, the average lag seems to be about 3ms, with about 10ms from Cardiff’s GB7CD over ja.net   Â

By all means feel free to connect your node adapters to the reflector. If it doesn’t work disconnect it. We wont ban you!

I got delivered the server for repair which had originally been donated by another Amateur. Formerly used as a rack mounted media server, no doubt to which it was very suited. But in terms of keeping something you want to maintain online for as close to 24/7 as possible then from the outset it was naturally the wrong choice.

Reading other repeater websites, it seems whilst groups have been forthcoming with funds for the ICOM hardware there has been a general over optimist approach to hardware dependability. Consider that in the first 4 years hard disks of server quality will fail at a rate of 10% a year. After 4 years this increases significantly year on year. Consider the user of lower quality, cheap consumer hard disks and you’re asking for trouble. The lack of any form of RAID on the original GB7CD installation was regrettable as without access to a working system or a backup of the user registered accounts you create yet more work for yourself when you come to reinstall the server.

Sticking in any form of cheap desktop computer with little more than desktop components even for a short time is pointless. You have to register users on it, do you really want to have to register them again if it fails a week later?
 

The Right Hardware

 

Quite frankly the number of people in Amateur Radio that are “experts” in computing never astonishes to amaze me. Before you decide to go build your own computer out of bits you have floating around, consider that you can obtain cheaply, maybe even free a quality rack mounted server 2 to 4 years old from many companies and corporations. On eBay even decent boxes are floating around for £150 to £400 with ample abundant parts should something go wrong. You might wonder why you obtain quality servers at prices cheaper than a comparable desktop. Its simple. Newer servers are more energy efficient. Imagine you are the Halifax bank and you have an installation of 1000 HP DL580’s; If you could replace those servers with hardware that’s maybe using 200 watts less and has more computing power, wouldn’t you drop the old ones too? 

What you’re looking for in server hardware is at least redundant disks and redundant power supplies. Depending on the server manufacturer and model you might have 2 to 3 power supplies all hot swappable. I’d suggest you have a spare sitting there in case one goes, reducing the time your machine doesn’t have a online spare. Notice I’m talking about keeping your box online for as long as possible. Surely that’s got to be the goal, and is it really justifiable to let the server fail for the sake of a few parts that together wouldn’t cost more than £50.

Cooling as with the RF side is important, hot swappable fans are generally the norm in server larger than the smallest 1U form factor, again keep a spare one or two so should a couple fail you don’t have to take it offline to protect the hardware.

Considering the low disk usage of the D-Star gateway software RAID 5 seems a bit like over kill. Opting for Mirroring with a hot standby seems more sensible, you should have improved read access and the ability to lose two hard disks.

Other options include getting servers with redundant ram and even redundant CPU’s. That’s where I drew the line, having a good pick of servers to chose from I did consider something like a HP DL580 with redundant RAM but it’s probably a bit overkill. I opted for an IBM x360. 2GB of ram installed and 4CPUs plus mirrored disks. I see no reason it won’t be running for the next 5 years without major problem. It needed before being installed on site a new FAN and a new Hard disk which were found for less than £50 for both on eBay.

Some pictures that might interest you:

D-Star compatible radios are available on VHF and UHF and microwave amateur radio bands. In addition to the over-the-air protocol, D-Star also provides specifications for network connectivity, enabling D-Star radios to be connected to the Internet or other networks and provisions for routing data streams of voice or packet data via amateur radio callsigns.

The first manufacturer to offer D-Star compatible radios is Icom. As of December 30, 2008, no other amateur radio equipment manufacturer has chosen to include D-Star technology in their radios. Kenwood re-brands an Icom radio and distributes it in Japan only.

 

D-Star Equipment 20th June 2009