I currently have a 1.5km 5GHz point-to-point link with 2 pcs of RB133C and biquad antennas. Now the bandwidth is limited at one end of the link to 10Mbps (limiting bw on the switch port where the RB133C is connected). This way, my connection is stable, the CPU usage on the RBs is 70-80%. If I turn off the BW limit, the CPU usage goes 100%, and packet losses occur.
There’s heavy P2P traffic on the link (most of it is Bittorrent), and the incoming BW is 100Mbps at one end of the link.
I’d like to upgrade this current connection, to be able to turn off BW limiting, and allow the highest possible BW to pass through, while maintaining adequate QoS (no packet loss, no insane PING times, etc.)
I’m planning to install parabolic antennas with dual heads for nstreme, and powerful devices at the ends.
I’d like to use mikrotik routeros, therefore I’m considering RB433AH with 2 pcs of R52H radios, or some kind of PC-based solution (Mini-ITX, with CF card, or SSD, and preferably passive cooling, and fully supported by Mikrotik RouterOS)
My question is: what endpoint devices do you recomment for this project?
Well it really depends on how much you want to do with the units on each end…
RB433ah or RB600 will certainly do a good job. With the proper setup they should be able to pass 50mbps+ with dual wlan cards…and still have the cpu processing power to do a good amount of QoS servicing…
Parabolic antennas and R52Hs should be more than adaquate to get the job done.
Until you upgrade can you turn of connection tracking, disable all packages you don’t need, and turn off ANA, also upgrade bios
This may help your cpu problem till you can replace boards.
Since I have a public subnet, and all my devices have public IPs, I don’t need connection tracking, I think. How can I turn it off? And what is ANA? I’ve googled it, and the first hit is this thread
For 1.5 km you don’t need any r52h cards. You will have to lower the power in connection with parabolic dishes. But do use parabolic antennas, as they will get you the maximum isolation from the “rest of the world” active in wifi in your area.
You can always go for a pc version, might get you only a little cheaper at first, but with lots of resources for possible later scenarios.
In my experience, if you have lots of noise in the area, you might get better results with bonding several simple nstreme links than with nstreme dual. This, again is from what I tried.
Also, if the only scope of the link if passing traffic, with no control over it, disable all firewall rules, and all unneeded packages if using rb. You get more free resources this way.
R52 are not too powerfull for the dishes, but for the distance, connected with the dishes. So, if you lower your power on the card, what’s the point in spending the extra money ?!?
Use this: http://www.zytrax.com/tech/wireless/calc.htm or some other calculator to see your power budget in connection with the gain of the dishes.
A too powerful signal might eventually burn your cards, ( if it’s waaaaaaay too powerful), or it might just “blind” the other radio. It would be just how you’d expect to talk to a person half a meter away, by shouting out loud, as hard as you can. He will sure hear you, but won’t understand a thing.
A -40 to -60 should be enough for 54/104 mbit link, provided there is enough clear spectrum for you in the area.
Thanks for the answers. Now I have measured the exact distance, and it turned out to be 1 km. I’ve tried the calculator linked above, but it"s quite difficult for me, and maybe I entered something wrong..
Could someone please do the calculations for me?
Antennas: prime focus parabolic, 44cm, 24 dBi gain
Cables: U.FL connector on R52 card → U.FL-N pigtail 15 cm → N connector → 5 meters of H-155 cable (attenuation: 0,6dBi/m ) → N connector on the antenna
Distance: 1 km, clear line of sight, one antenna is on the top of a 10-floor building, other is on the roof of a 2 floor buildng.
The question is: what TX power should I set on the TX radios?
I’d like to set up everything before installation, I hired the local satellite guys to install the antenna mast, and the dish on the 2-floor building, because I don’t have the tools and experience to do it alone, and also afraid of falling down… However, they’re TV guys, don’t know anything about WiFi. I thought I set both ends to alignment-only mode, so they only have to listen to the beeps to align the antenna on the roof
With TX power set to +17 on both sides, I can only get -70 on the RX radios. Why are these values so low? Someone previously wrote me that I should expect a -40 to -60 RX power, with lowered TX powers.
The other strange thing is, that at one side, the TX radio sees the RX radio, and vica versa, with -20 RX power. Is this acceptable?
