Has anyone ever setup a d-star reflector on the mesh (dxrfd)? It sounds like an interesting concept, perhaps using G4KLX and the WesternDStar image on a pi.
I have a the WesternDStar on a Pi. I need to figure out how to add a custom reflector IP.
Thinking that this would be good for hams who have a DStar capable radio to participate "on the mesh" to service EMCOMM needs.
anyone else interested?
What's the real capacity of a D-Star link? Can it even handle the overhead traffic of the OLSR protocol?
I think you are really asking "what is the bandwidth requirement for a successful d-star connection across the mesh", right?
That is something I'd want to research (snmp metrics should help), but, if it can be done on HF..... I think our odds may be good.
Well, you can get an idea of the traffic requirements by running tcpdump or wireshark on the OLSR "hello" packets coming out of each node every 2 seconds. They're UDP broadcasts to port 698 and vary in size. They relay link topology information, lists of IP address aliases, attached networks (HNAs), host names, service announcements, IP address aliases, and so on. They run continuously even on an idle network, as the other nodes use them to determine connectivity and maintain their routing tables and host lists. And they can get quite large as the network grows, because all that information "floods" around the entire net.
OLSR is an example of a "proactive" routing protocol, one that sets up complete routing tables in advance of their being needed. An alternative is a "reactive" routing protocol that doesn't find and set up a route until it's actually needed, so there's little or no continuous background overhead. Obviously that can take longer, but it might be more practical on a very large network with frequent topology changes and relatively little user traffic. Neither class of protocol is always superior to the other, which is why both are being actively researched and experimented with. This is one of those things for which there's little substitute for operational experience.
OLSR traffic is not relevant to running DSTAR on an AREDN network as OLSR will not be routed over DSTAR.
AREDN provides an IP (TCP/UDP) network that programs (such as DSTAR reflectors) can run across just like cameras, email servers, winlink, etc.
Can't say I've tried the DSTAR reflector over mesh (largely because I don't have any DSTAR repeaters) but don't see why it wouldn't run. A key of course would be make sure no encryption (I belive there is crypto for the official dstar network, not sure about non public private reflectors) and having reliable links that are not dropping packets since audio is very time sensitive.
yes. I certainly was not suggesting OLSR traffic would go over the Dstar network. After the beta work is done, I may bring up my hotspot on the network and take a look.
Well sure, if you don't mind manually configuring the subnet that you're routing over the mesh, and reconfiguring it if it moves to a different node.
The whole idea of a mesh is that you can arbitrarily move the individual nodes around and they'll just adapt automatically without having to change their addresses. But it does end up to be a tradeoff between the convenience of automatic reconfiguration vs the not inconsiderable overhead involved.
Darryl,
did you ever do anything with this idea?
73 Ruud
Bandwidth requirements for a dstar conversation are trivial. 16kb/s of bandwidth per conversation. Latency needs to be consistent, and the lower the better.
EDIT to change software name...it's dxrfd.
drxfd seems to be google-proof.
I run a private DSTAR reflector (so-called X-Reflector) here using the "dextra" software (dextra_reflect). I think the only demand it places on the network is to have two ports open and you can configure which ones it uses (although there are standard ones in use). As mentioned the reflector has to be on a different computer than the repeater which it is "reflecting".
I should note that a reflector is not needed to tie just two DSTAR repeaters together. You need it only for three or more repeaters/users or if you want to stream audio to two repeaters at the same time (mine is used for bulletin transmissions).
Ken
KE2N