Posted: Mon Nov 08, 2010 18:48 Post subject: Setting up multiple wireless bridges
Alright...I have a fairly straightforward problem and (at least I think) a fairly straightforward solution.
I have two buildings on my property separated by a couple of miles or so.
I have a T1 line connection to one and want to share it with the other.
Now between these two areas is a pretty dense section of trees, HOWEVER an electric line right-of-way goes straight through.
My thinking was this...Set up a wireless link using multiple repeaters (has to be about three or four because the ground is NOT level...several hills to overcome, etc.) along the path of the right-a-way with perhaps a directional high-gain antenna on both buildings pointing directly at the closest repeater.
But then I kept reading and found out that each single radio repeater will cut the total network speed in half at each "bounce" point
While it probably wouldn't be that big of a deal (since it only needs to overcome the 1.5mbs of the T1 line...I don't require a 54+mb network connection, etc.) I'd rather put my time and money into something that could, in theory, be extended indefinitely if later needed.
For each of the "repeater" stations, for example, I'm already looking at solar panel setups so I don't have to worry about powering them, etc.
So, I then started down another road (inspired when I discovered the DD-WRT page in fact)...what if instead of installing single repeaters in each of the stations, I instead installed TWO routers (set to different channels, etc.) and instead of "according to Hoyle" repeat the same signal, basically have each station create a little network BRIDGE between themselves -- culminating with bridges between both ends of the chain and each of the buildings.
I'm curious what the thoughts are of the learn-ed ladies and gentlemen here on this plan?
Is it feasible? How difficult is it going to be to have several wireless bridges working in harmony with several wired connections in the middle (meaning where the pairs of routers would be directly connected together with Ethernet)?
Past the physical problems setting them up...how difficult is it going to be to pass routing information through the system so I can the T1 router properly be able to assign an Internet-Routable IP address to the router in the building at the end of the link?
For most users; the first, and best solution would be to use a parabolic (dish) antenna on either end; and pushing some heavy power; to "bite through" the obsticles.
Check on the "Notable Links" of reference A; range is not an issue; only going through very dense forests/earth (hills, boulders, etc).
The second method would be putting a single bridge, on a high point between the 2 points; also using directional (yagi/panel) antennas.
The third feasable solution; would be to use several bridges; utilizing non-nat'd, routed local ips, as shown below; cycling channels (only use channels 1, 6, and 11) to eliminate interference from the 2nd closest AP. For cleanliness; you could even setup a PPTP server on DD-WRT 1; and have DD-WRT 5 "VPN" into it; so devices will appear to be on the same network.
If you have the budget for option 3 (several individual solar panels, battery packs, antennas, and networking gear), your better off getting towers setup and going with the first solution.
The real question comes down to distance, and budget...
If it's only a few miles; and your not going through any major obstructions; or if you have a decent budget (or have access to 2 old antenna towers); go with the first route.
If it's 3-10 miles, and your going through a mountain; go with the 2nd route.
If it's 10+ miles; or an extremely dense forest/several obsticles; go with the last one.
For most users; the first, and best solution would be to use a parabolic (dish) antenna on either end; and pushing some heavy power; to "bite through" the obsticles.
Check on the "Notable Links" of reference A; range is not an issue; only going through very dense forests/earth (hills, boulders, etc).
The second method would be putting a single bridge, on a high point between the 2 points; also using directional (yagi/panel) antennas.
The third feasable solution; would be to use several bridges; utilizing non-nat'd, routed local ips, as shown below; cycling channels (only use channels 1, 6, and 11) to eliminate interference from the 2nd closest AP. For cleanliness; you could even setup a PPTP server on DD-WRT 1; and have DD-WRT 5 "VPN" into it; so devices will appear to be on the same network.
If you have the budget for option 3 (several individual solar panels, battery packs, antennas, and networking gear), your better off getting towers setup and going with the first solution.
The real question comes down to distance, and budget...
If it's only a few miles; and your not going through any major obstructions; or if you have a decent budget (or have access to 2 old antenna towers); go with the first route.
If it's 3-10 miles, and your going through a mountain; go with the 2nd route.
If it's 10+ miles; or an extremely dense forest/several obsticles; go with the last one.
V/r,
Mike
AH! I never thought of that (speaking of VPN).
That answer my second question pretty well (my concern over the T1 router successfully passing Internet-routable IP addresses I mean).
The reason I asked about expandability is because at some point in the future, I might need to expand Internet into a another building in the same vicinity (and I wanted them both to "feed" off the same chain of bridges so neither was dependent on the other, etc.).
By setting up a VPN tunnel from the first DD-WRT router (the one connected directly to the T1 router), then I can simply create a VPN tunnel from it to the DD-WRT router Building "A" and it would be as though they are connected directly(so long as they can communicate through the bridges, I mean) -- the T1 router doesn't need to worry about any of the steps between the two routers.
And in the future, if I add another DD-WRT router in building "B", all I have to do is connect the last "bridge" DD-WRT into an AP so both building "A" and building "B" can both connect to the end of the chain AND THEN simply have the DD-WRT router in both buildings create a VPN tunnel to the DD-WRT router connected to T1 router and they should behave as though they all three are in the same room.
on this plan?