Newbury hello! And hops/routing questions :)


#1

Hi hi!

I’ve just got and set up my mesh devices :slight_smile: Is a little thin on the ground where I am in the UK. I am running a powered node and am keenly awaiting txTenna :slight_smile:

Out of curiosity I am interested in how routing is achieved and how the hop count will be increased…

I am assuming that there is no routing and that a node will just rebroadcast any message not intended for itself. With this assumption in mind, do nodes have to keep a list (maybe a hash?) of every sent message so they don’t retransmit one already relayed in an infinate loop? Does such requirement essentially limit the number of allowable hops? I know that infinate hops has been discussed, but I am interested in how this is possible at any volume with no routing and limited memory to store lists of relayed messages. I can imagine an individual node could see the same message many times.

Anyway, I’m looking forward to having more fun with my goTennas :slight_smile:


#2

Hi Marc,
Welcome to the community! :smiley:

Here’s my simplistic understanding of how hop count works. Each time the message is forwarded, the hop count attached to it is incremented upward by one. Any goTenna (not just the stationary nodes) will forward the message in this way until the max hop count is reached and read when it is received, then the message is no longer forwarded per the firmware version limit on that goTenna.

The vagaries of radio reception provide alternative pathways between sender and recipient, which are dependent on local conditions. I can’t speak to how routing in whatever form it may take works beyond that.


#3

Thanks for the reply :slight_smile:

Yep, the hop count increment makes perfect sense. The thing I get stuck on is how infinate hops can work without causing loops or requiring a lot of memory to record “seen” messages.


#4

I rather suspect there aren’t infinite hops, except in theory. Infinity doesn’t compute well, but a really big number should do the trick.

That said, there is a limit on the number of transactions per minute that the firmware enforces. It could take a long time to get to infinity…

In reality, there’s very limited need for infinite hops if you think about it. Who do YOU know that lives that far away? :stuck_out_tongue_winking_eye:


#5

Just thinking of the practicalities of a truly decentralised system at scale :slight_smile:

I get your point but I communicate with loads of people I don’t know :upside_down_face:


#6

I guess also because I’ve come here from the news of txTenna, that’s a vastly different application than enabling person to person communication for small communities or hiking groups.


#7

Shouts will help you talk with people you don’t know, provided they have a goTenna.

Generally speaking, my tendency is to text specific others. You have to know their UID or vice versa to do that. txTenna can serve as an intro between folks, in that it establishes a relationship, at least temporarily, which can lead to that initial exchanges of UIDs. So txTenna is an incentive to acquire and use a goTenna as you have found.