[Question] Can yo chain modems to deliver messages?

I'm trying to set up a internet system where I can brodcast a message to computers w/modems outside of 64 blocks. Is that possible?

Yes, you would use a relay method which would be fairly simple to make.
Computer A sends a message to Computer B, which passes the message on to Computer C.

Here is an example or a extremely Basic Router

Spoiler

local tArgs = {...}
if #tArgs ~= 2 then
    print("Error Usage : <computer one ID> <computer two ID>")
    return
end
local function openRednet()
    local listOfSides = rs.getSides()
    for i = 1,6 do
	    if peripheral.isPresent(listOfSides[i]) and peripheral.getType(listOfSides[i]) == "modem" then
		    rednet.open(listOfSides[i])
		    return listOfSides[i]
	    end
    end
end
modemOn = openRednet()
if not modemOn then
    print("No WIFI ModemnPress any key to return to menu.")
    os.pullEvent("key")
    return
else
    print("Opened wifi on "..modemOn.." side")
end
local comp1 = tonumber(tArgs[1])
local comp2 = tonumber(tArgs[2])
if comp1 == nil or comp2 == nil then
    print("Error Usage : <computer one ID> <computer two ID>")
    return
end
while true do
    local e,e1,e2,e3,e4,e5 = os.pullEvent()
    if e == "rednet_message" then
	    if e1 == comp1 then
		    rednet.send(comp2,e2)
	    elseif e1 == comp2 then
		    rednet.send(comp1,e2)
	    end
    end
end

interesting function, thing is you have to set up every computer individually, I designed a function for this but it needs fine tuning

KaoS, on 12 August 2012 - 08:07 AM said:

interesting function, thing is you have to set up every computer individually, I designed a function for this but it needs fine tuning

Thanks. I designed it as a simple system. When you start getting into packet routing in a more hardcore scene things become huge and complex quickly. So it has one simple job send packets from a to b and packets from b to a. If I started adding other stuff like routing tables, IP's ,TCP and Internet it would become several hundred lines long. Yes the added complexity means added functional But I find in most cases this simple little script running on a satellite will do all I need.

yeah, I would use serialized tables to contain the message, the relay PC would check it its ID is in a list and if not it would broadcast the message and then the table with its ID added in so each PC could only send it once. I suddenly realised that I would end up with duplicate messages if the following happened:

C=the main computer sending the messages
O=a relay PC
P=the relay computer where the problem starts
arrows are message transfer

O->O->P<-O<-O
^     ^     ^
|     |     |
O<-O<-C->O->O

so basically you now have a computer with 3 copies of the same message with different ID lists

PS I really hope this font has fixed width chars

KaoS, on 12 August 2012 - 09:10 AM said:

yeah, I would use serialized tables to contain the message, the relay PC would check it its ID is in a list and if not it would broadcast the message and then the table with its ID added in so each PC could only send it once. I suddenly realised that I would end up with duplicate messages if the following happened:
– snip –
so basically you now have a computer with 3 copies of the same message with different ID lists

PS I really hope this font has fixed width chars

yep the message would be duplicated many many time also when scaled up It would scale the amount of duplication. I gave up on that concept and went with something else In the routing system I am developing currently.Packet routing in a mesh net is a problem that has still no fixed answer in the real world. The Internet only functions because a dedicated group of individuals maintain it. They manual add routing tables and tell the system how to function.
Example a packet from America goes to the neared under sea cable because It was told to be a Technion in a routing table. Then when arriving in the other country goes to the local exchange for the user because IP address ranging from 000,000,020 to 000,000,030 are given from that exchange.then the exchange sends it to the user because when the user connected to it it asked for a IP and the exchange used one from its allocated range again a Technion installed this range. The Inter net only works because the routing tables are maintained. when this stops so will the Internet. Unless adaptive mesh net systems are created that can rout based on other characteristics.

So the problem is a lot bigger that it first seams. In CC we can work around this quite simple By managing our own routing tables.But that is quite complex. so making a user friendly system will always be a challenge.

yeah, tell me about it, I'm only just out of school, no programming experience other than a little fiddling in vbs… making such complicated systems still takes me a while… but I will get it right

I actually built a turtle deployment system that will put a computer every 16 blocks, hidden underground. With 1.4, though, I might want to have it put the computers high up…
Nonetheless, all I need to do is just get the turtle to run a program on the computer. The only viable method I can think of is to edit the server/global startup.