[ax25-layer2] Backbone (was: The lights.)

[Andre PE1RDW]

James Ewen schreef:

>
> So, can we discuss this in a little less vague manner, but not delving 
> so deep that we determine individual bit settings?
>
> If the TNCs are going to be used as layer 2 devices, then they simply 
> transmit packets to the local area.
>
Not really, the connection control frames are a part of ax25 layer 2, 
with a kiss tnc you have a layer 1 device so the layer 2 stuff happens 
in the pc.

> With no capability of doing any type of connection between TNCs, then 
> there is no network, so therefore no need for a layer 3 that looks 
> after routing.
>
Even without connections you can still set up a network, you just move 
the connections from layer 2 to layer 3 or even layer 4, not ideal for a 
rf network but it works, however the connections are still there, they 
just move from the tnc to the pc (or other controlling device) when used 
as a kiss tnc.

> What type of solution is proposed? Assuming that a wired ethernet 
> layer will be available at all TNCs is not acceptable. Perhaps a 9600 
> baud UHF backbone could be used to implement routing, but that will be 
> a significant cost outlay, and build out time frame, not to mention 
> the fact that some areas may not have the luxury of being able to 
> implement such a system.
>
If you want a working network you will need a backbone, preferably a 
19k2 or better on 23 cm but 9k6 on 70cm will work too.
If you put the network on the same frequentie as the lap then you will 
reduce the troughput to a crawl.

> Am I out in left field? Where does the routing go to when it is 
> removed from the TNCs? The NSR concept doesn't appear to remove layer 
> 3 functionality from layer 2, it simply removes the ability of the 
> user to control where packets go, and hands it over to someone else.
>
The routing simply moves to whatever is controlling the tnc, be it a pc 
or a specialized controller, nsr in my view is a simple repeater without 
user control and could never replace a layer 3 implementation.

> A network of TNCs with the network capabilities removed leaves me 
> looking at a bunch of hardware that can not talk to anywhere.
>
Then stop thinking of a network of tncs and start thinking of a network 
of nodes, tnc firmware is generally to limited to run in a good working 
network.

> James
> VE6SRV

73 de Andre PE1RDW