We are in the process of doing a site survey for a wireless network using NL-2511MP 200mW prism 2.5 mini PCI cards and router board 532’s. We have a simple setup currently running mikrotik 2.9.19 beta. We are using a 12dB directional antenna on the router board end, with the router board mounted in a plastic enclosure, up a three meter mast on top of a large hill. For the client end we are using a Seano prism 2.5 NL-2511CD in a laptop, running windows XP with the latest drivers from Seano.
When standing right next to the router board, or 100 or so meters away, there is no problem, we can ping the router board from the laptop infinitely with 2-3ms Ping times. However, when testing from 3+ KM away, using a 19dB parabolic dish the ping time becomes unreliable and repeats the following pattern:
Pinging 192.168.10.1 with 32 bytes of data:
Reply from 192.168.10.1: bytes=32 time=12ms TTL=128
Reply from 192.168.10.1: bytes=32 time=28ms TTL=128
Reply from 192.168.10.1: bytes=32 time=84ms TTL=128
Reply from 192.168.10.1: bytes=32 time=120ms TTL=128
Request timed out.
Reply from 192.168.10.1: bytes=32 time=11ms TTL=128
Reply from 192.168.10.1: bytes=32 time=29ms TTL=128
Reply from 192.168.10.1: bytes=32 time=73ms TTL=128
Reply from 192.168.10.1: bytes=32 time=134ms TTL=128
Request timed out.
Reply from 192.168.10.1: bytes=32 time=10ms TTL=128
Reply from 192.168.10.1: bytes=32 time=43ms TTL=128
Reply from 192.168.10.1: bytes=32 time=89ms TTL=128
Reply from 192.168.10.1: bytes=32 time=121ms TTL=128
Request timed out.
The response time slowly creeps up then times out, and then repeats the process.
We have yet to try this with 2.9 rc1, as I notice it has just been released.
Any suggestions welcome, I am happy to provide more information where required.
this is almost always issue of interference. Try to do /interface wireless scan name-of-wireless-interface, or /inter wirel frequency-monitor you will see what is ‘in the air’. Then, choose the most free channel, as far away from competitiors as possible.
Also, you have to understand that these conditions can change rapidly. I would recommend you to watch your pings/throughput for three-four days and try different channels (two or three least occupied). There are huge differences.
This is the strangest interference I have ever encountered. Its in the middle of the country 2km away from a town of 100 people with one wireless internal access point at the airport.
I have dealt with a lot of inner city interference before and usually the result is consistent timeouts or extremely high ping times. I have tried all three usable channels 1, 6 and 11, the problem persists.
I have done many setups like this, although this is the first with a 532 router board and the mini PC 200mW card.
May I point out that the router board was running a second mini PCI atheros card, connected to a 9dB omni antenna which we were able to connect to from ~10km with 3ms constant ping times.
I will try to replicate the problem, back in the city, to generate the support file.
I have exactly the same problem and not with PRISM only. It behaves with Atheros exactly like this. At the same time my OWN AP, built on LINUX with Wavelan HOST AP (Lucent/Orinoco/Avaya) - Behaves perfectly. So I’m hardly disappointed with MT AP support and that must be fixed
if you will not use your 4W amplifiers, you won’t experience anything like this with Atheros.
Remember, MT is just software, moreover based on Linux.
Not software, but radio-frequency engineering is causing your troubles. Cables, pigtails, 4W amplifiers (I doubt you really need them), antennas, interference from competitors in the air, all this makes its own part to your “mikrotik” problems.
Guys, do not tell me that. And read my previous message more carefully - I DID REACHED EXCELLENT PERFORMANCE with another AP on the same freq. Just it is HOST AP, built on Orinoco and linux and Pentium 1 pc. I still use it, since MT just did not worked for me, when I tryed to replace it. I did tryed with amps, with no amps and whatever. My 2.4GHz links are from 1 km up to 30 km. AND WORK EXCELLENT on hostap!!! Try to reliably reach 30km with 11dbi omni antenna and 100mwt-200mwt clients - and i will laugh, when you try it, if you do it with no AMP. I have over 8 years of wireless experience, and I KNOW what I’m talking about.
Right now i do use MT for backbone only on 5ghz (yah, 70km link, guys), and just on a few places for 2.4G AP - but with customers only 1-2km far. Then it works OK. IF you connect a far located customer - the problem appears.
I’m very keen to deploy MT 2.4G AP’s - BUT I NEED more stable behaviour, since I run VOIP over that links. And even latency jitter is problematic for VOIP.
Or I would be gratefull for unofficial Orinoco HOST AP package for MT, since when I installed orinoco card to MT - I found that MT does not support Ap on orinoco cards.
Have you tried another similar brand card in that AP? Sounds like your radio might be toasted.
As for the amp + omni, that’s a long way to transmit with an omni and clients on the other end with only 200mw. Have you considered sectorizing your POP with 3 sectors instead of one omni? If the RF is available, I think you’ll find it works much better, and you won’t need amps.
… I’ve already written (see my posts above) I DID TRYED atheros too.
I suppose that claiming bad behaiviour of an AP mode - is a very and very bad thing for MT - and they should try to confirm themselves, and not do like every other vendor, just reject such a cases, putting full responsibility to a customer. I’m not only one who have such a behavior of the MT box. You should consider this sign seriously.
It would be much better is Mikrotik tries to actually TEST it’s own AP in multiuse environment with different (NON MT!) client equipment, located at different distances (1,3,5,10,15 km far) from MT AP. I’m quite sure that you will see the problem yourself. But you should use just generic client equipment, like DLINK, LINKSYS WRT, and PC Orinoco clients. (Who knows maybe on 802.11b even MT will behave so, but i did not tried that)
you know that this is a on going issue now MT will say it the radios . which it is most likely but there still needs to be a better solution . i have this similar issue . the only way i have fixed it is to limit the radio to 6mb only on 5ghz
I ended up having this very same issue and belive I have a solution for you.
I had planed on doing another relay and had placed some static routes in the MT unit to relay to the next unit. But that unit was not in place yet. So as people scan ip ranges and such it was causing a loop.
I was going from 4-7ms pings to 200-300 for 5-6 times then the interface would time out once, drop back to 4-7.
Removing the statics routes that did not exist yet, and removing the static routing in my cisco that pointed the route over my wireless link has solved the issue.
This is a plain RB532 setup with no routing, no bridging. It just has two wireless interfaces, an Atheros and a Prism 2.5. Each interface has its’ own /24 subnet defined. It is just a base install, at the time of 2.9.19 beta. Will try again with RC4 now it is out.
Try it without them and see if it makes any difference.