I’ve had a 31 mile PtP link with Ubiquiti XR5 cards for around 2 months working great. Signal -58db / -59db. 54Mbps2 x 54Mbps2 with 100% CCQ. Yesterday, I switched the cards out with SR71-15’s, in hopes for better throughput. Even with both Chains, the data rates are horrible, sometimes worse than the XR5 cards at around 54Mb x 24Mb.
I know the new 5.0 beta firmware is supposed to “improve performance over long distance links”, however, I cannot risk beta on this link, and it seems as if its taking an entire year to get a stable version of this so far. My question is:
Does anyone think the 5.0 FW will fix the issue (if not otherwise I will switch back to XR5’s before winter hits)
Does anyone believe the latest 5.0 beta FW is stable enough to use on just a PtP link using WDS.
Also if anyone has any tips on adjusting the settings to get good data rates on 802.11n over long distances please let me know. I tried disabling CSMA, which had no effect. The last time I tried adjusting the Nstream settings for Framer Policy, it had only made things worse so I just leave it at default settings..
FYI, I use 5.0rc1 on all my long-distance 802.11n links with good success. I do not, however, recommend using NV2 with them.
All that said, I am about to downgrade back to XR5 due to the issue with missing dBs in ROS with the SR71-15. I need more power more than I need the extra Mbps to overcome early morning fades.
I’ll try to get some screenshots up soon. I must mention, I have configured the radios exactly the same way I do with the rest of my PtP setups that are ~10 miles. I just assume the long distance is the cause of degraded performance.
WDS - Dynamic / Bridge1
Nstream - Enabled
Polling - Enabled
Disable CSMA - Not Enabled
Chains 1/2 both Checked
HT Extension Channel - Above Control
Signal Strenth -62db / -63db
Signal To Noise - 59db
Tx / Rx Rate (currently) 104.0Mbps-HT / 39Mbps -This changes constantly, every 5 seconds or so
OK so I upgraded the link with the v5.0rc1. No Change. The signals are exactly the same, and the throughput is exactly the same.
On the wireless config tab, I notice now there is “Wireless Protocol”, which is selected to “Unspecified”, even though “Nstreme” is check on the nstreme tab…
The options are:
802.11n
Any
Nstreme (why would they have you select it here AND on the nstreme tab)?
Nv2
Nv2 Nstreme
Nv2 Nstreme 802.11
This is really getting confusing now. What settings do people use to get maximum throughput? As of right now, the firmware upgrade has done nothing…
So I noticed about 5Mbps TCP increased throughput on sending only. I upgraded the next link down, and lost replies back from that Mikrotik. The station Mikrotik is physically hardwired to this Mikrotik, and I can only get a few pings back once in a while. Looks like I’ll have to make a site visit. Mikrotik
So I had to run out to the tower (1 hour away) to see what the problem was after upgrading to 5.0 RC. Here are the results. Not happy.
Speedtests showed an increase of 5Mbps TCP in between the mikrotiks. ACTUAL speedtests on laptop DROPPED 5Mbps.
I kept losing connection to the Mikrotik (slave side) when going through the switch. However, when plugged STRAIGHT into the Mikrotik ethernet, it seems somewhat stable. The only way I could stay connected long enough to downgrade to 4.11, was to keep disabling and re-enabling my network card. VERY unstable on the ethernet side.
Latency also, using nv2 nstreme had increased to 3-4ms between mikrotiks, rather than the good old 1-2ms.
This is a point that connects 3 towers together, and I was losing pings and even MAC connections to all of them when on 5.0 rc. After downgrading back to 4.11, everything is back to normal. I really hope Mikrotik gets there $#!& together soon before releasing 5.0 official.
Ya I had it to “Above Control” before, and I switched it to see if it would change anything, but no. I’ll try the HW Retries thing, although I thought that only helps if the station keeps disassociating.
UPDATE: Changed HW Retries to 15 and Above Control. No Change. The RX data rate drops from 106Mbps to 39Mbps-HT when running speedtest, then goes changes up higher when idle.
Since I know it is a distance issue, I tried to manually set the ACK. I set it to 372 (roughly 32.7 miles) to give myself a little overhead, and the data rates are now 216.0Mbps-HT / 216.0Mbps-HT
Well I think that may have just helped on that particular link. I have another link at 25 miles that is always stuck at 150.0Mbps-HT / 39.0Mbps-HT. I tried the same thing on that link, with no improvement
Colebert, can you only adjust the MCS rates on 5.0? Because I can’t use that, due to ethernet link instability..
Do you uncheck all the MCS rates except 10 on both supported and basic? Because I didn’t have any link after that. Then I tried all 4-10 rates, still nothing, then I tried 0-10, nothing, I could only get the link back by going defaulting all the data rates again…
Not sure on the ACK thing, it seemed to help, maybe it was coincidence?
Ya I’ll have to wait on that until I have someone at the tower in the case that it doesn’t link back up! Thanks for everyone’s help on this though. I still wish I could push full data rates at long distances. The signal is excellent and the noise floor minimum. I have other links at just a few miles with the same signal and noise floor, and I can push 300Mb-HT/300Mb-HT with 100% CCQ. I guess this is as good as it gets with Mikrotik, as it doesn’t look like the highly anticipated OS 5.0 is going to be any improvement on PtP links.
