[Dxspider-support] More about routing.

Dirk Koopman djk at tobit.co.uk
Sat Jan 18 13:55:27 GMT 2003


On Sat, 2003-01-18 at 13:34, Filip Jonckers wrote:
> Hi Dirk,
>  
> I'm not as well informed about the PC protocol as you are.. I know you studied this over and over ...
>  
> but isn't there a way to use some sort of TTL (time to live) value for users/nodes
> maybe keeping entries only for 24 hours (or less) in the table
> users staying connected longer than 24 hours are still a minority - even using internet connected nodes
> this could help cleaning up ..

The users are not usually a problem. It is the nodes. There are all
sorts of possibilities for improving matters if you have control over
the protocol and who you are talking to. 

The problem is that I have been trying to remain totally compatible with
the PC protocol and there is no way to do that (AFAIK) and stay
compatible. Nodes will stay connected here for days at a time.

In NP there is precisely this type of timeout arrangement. Each node is
required (once a hour, provisionally) to broadcast all the callsigns
connected to it (both nodes and users). If no broadcast is heard from a
node within 3 hours, it is deleted from the nodes table. There are no
long bursts of PC19 and PC16 on startup because all a node ever
broadcasts is just its own local config - not what it thinks it is
connected to.
 
I am still in two minds as to whether I actually broadcast user
information at all. I am minded to allow the network to acquire user
routing information from talk, announces, dx spots and so forth and rely
on (intelligent, directed) broadcast for talk messages. Afterall the
only reason that announces annoy so much is that they are being used to
implement talk! If the users learn that talk <call> will always work if
<call> is online somewhere. (Actually ann/full <call> == talk <call> in
NP anyway).

Unfortunately I suspect I won't get away with this for human engineering
reasons...

Dirk
-- 
Please Note: Some Quantum Physics Theories Suggest That When the
Consumer Is Not Directly Observing This Product, It May Cease to
Exist or Will Exist Only in a Vague and Undetermined State.






More information about the Dxspider-support mailing list