Multiple connection in mesh net

[oleksandrm]

Hi guys , i'm using nRF mesh library  nRFMeshProvision 2.2.3. I'm trying to connect to multiple mesh nodes and send message to all of them. In provided class NetworkConnection.swift i see next words:

// Find the first connected proxy. This may be modified to find
// the closes one, or, if needed, the message can be sent to all
// connected nodes.

so i implemented my idea like this 

func send(_ data: Data, ofType type: PduType) throws {
    guard supports(type) else {
        throw BearerError.pduTypeNotSupported
    }
    
    proxies.forEach {
        if ($0.isOpen) {
            do {
                try $0.send(data, ofType: type)
            } catch  {
            }
        }
    }

    //***** this is original implementation that send message to the first open node 
    //        guard let proxy = proxies.first(where: { $0.isOpen }) else {
    //            throw BearerError.bearerClosed
    //        }
    //        try proxy.send(data, ofType: type)
}

Is it correct way to achieve my goal? I'm asking because sometimes i get crash

Thank you

[oleksandrm]

just tried to update lib to 3.0-beta1, and got next crash:

Guide me please , how properly send message to all open connections

Thanks

[Aleksander Nowakowski]

Hello,

I'll look into the issue in 3.0-beta1 that you found. 

I have just one question: why do you want to send the same message to more than one node?

[oleksandrm]

on 2.2.3 it was happening (if i'm not wrong) every 2-5 mins. i really can check it again if it helps somehow

[Aleksander Nowakowski]

Yes, the first issue in 2.2.3 was reported on GitHub and has been fixed in 3.0-b1. i haven't seen the latter one yet.

[oleksandrm]

Got it, i will run more tests today with 3.0-b1

[oleksandrm]

Hi, i'm using version 3.0-b1, and can't reproduce any crashes

Small question: what cons i get when i send message to multi nodes in order to get faster communication speed? Maybe there are other options to consider?

Thank you

[Aleksander Nowakowski]

• It makes sense to send a message directly to the destination node, or one that's close to it with small ttl value, as then the message isn't propagated via adv bearer or just with few hops. But sending the same message to multiple nodes not knowing which is them, if any, is the target is not needed. Each of those Nodes will relay the message immediately on adv bearer, so all other nodes in range will get it moment later. There is of course more lag, or risk with losing a packet, but that could be fixed by increasing Network Transmit and Relay Retransmit properties on Proxy nodes. That should be enough.