MikroTik

I am experiencing low bandwidth test from a single tcp connection over nv2 protocol. This problem is not present over nstream protocol. since nstream has some disconnecting problems i have preferred using nv2. Or should i not use nv2 and nstream at all? i seen many posts in the past about this but not any solution so far. nv2 protocol dosent let u any option for tuning. even when i change the tdma timing offset option on the nv2 section of the ap wireless interface it hasn't any effect on the connection. i am using wds.

Did you try Bridge to Station-Bridge vs WDS?

I've experienced same issue just a few days ago. After extensive research and some tweaking I was able to get some answers. I'm not sure about your setup but I suspect you have multiple p2p/p2mp links with nv2 (from internet to client/ap). I don't know the exact cause of this but nv2 in Mikrotik donẗ like to be stacked one after another. I suggest that you use nstreme -> nv2 -> nstreme (exact size - 3600+) -> 802.11n or some combination like this. From my personal experience I fell in love with nv2 (and still am) but if you put nv2 everywhere this is what happens. My advice to you would be to monitor how much traffic is going through your AP and tweak your p2p links accordingly. Another thing I've noticed is that even though Nstreme has higher latency and more ping loss when doing BT test (UDP) there's not a big difference in TCP test and Nstreme actually works better so it really depends on A) how much Bandwidth you need B) how important is latency for you.

It seems to me that ideal would be to co-operate with some of your client and ask them how's their internet connection with nv2 vs. Nstreme. Another thing to keep in mind is that nv2 is easily disturbed by other clients in the same channel and also disturbs other channels. Focus on your main links (bridges) and choose protocols wisely but I like to use nv2 for clients because of latency-to-throughput ratio.

btw: also try to use
1. bridge -> station bridge
2. use mq-pfifo on your interfaces in Queues (if you have multi-core router and don't use Queue Tree)
3. BT test from powerfull enough devices

Yes i just tried now with station bridge and its the same result.

I switched already another ap to nstreme with some tweaking and is working a lot better. even though other antennas connected to it disconnect sometimes, throughput is a lot better compared to nv2. nv2 seem to be a disaster on point to multi point maybe in noisy environments.

Elliot can i ask you why use nstreme (exact size - 3600+). what is the purpose to it? i was thinking what could fix the disconnecting issue

Elliot can i ask you why use nstreme (exact size - 3600+). what is the purpose to it? i was thinking what could fix the disconnecting issue

Sure you can. I'm not a guru in terms of Mikrotik devices but over last year I've only one job - to make link as good as possible in heavy noise/interference environment. I've tweaked over 1000 antennas so I know a few things that works etc. Exact size is basically what size of frames will Mikrotik send to other side. "Exact size" does that Mikrotik will send 1 frame with exactly 0-4000 packets, if there's not enough packets he will wait. "Dynamic size" means that Mikrotik will stack packets into different sized frames depending on his (Mikrotik/Processor) algorithm. From my experience "exact size" will give you the best throughput with the lowest latency and most importantly ...almost no ping/packet loss. Best case for me is between (3200-4000) that!s why I've told you to set in on "exact size - 3600+". If you want another tips tell me more about your setup and in what kind of environment does it operate, also what's the distances, how many clients, how many channels free (or not free) etc.

As for your disconnecting issues I've experienced it with Nstreme only once or twice. Key problems that you need to check are:
1. what kind of interference/obstacles are there in the area of your clients and/or APs
2. how far away are your other AP (They could create interference/noise for themselfs)
3. do you use "ap to clients protection" on APs and "client protection" on clients + you can you HW protection on clients as well
4. preamble mode - short on both sides can work magic sometimes
5. also in Nstreme do you have checked Polling and Disable CSMA and Nstreme ? if not ...you should
6. What kind of antena and power do you use ?

I suspect that you disconnections problem could be cause by couple of things
A: incorrect alignment (do they have MIMO?)
B: incorrect setting of Tx Power (clients and or/AP are oversaturated, overpowered on short distances)
C: incorrect choice of channel + wrong channel width

anyway I'm glad I could help. Please do let me know how did you resolve or didn't resolve this issues. Have a good one mate and don't forget to test and tweak in real environment because it's the only way how you can setup your routerboard exactly to fit your needs.

Also if you use some kind of security profile do not use TKIP and only AES.

Thanks Elliot.

1. There are no obstacles but a lot of interference i guess since it is urban area. I think there might be a problem with noise detection on routeros or on wlan chipset itself since noise floor threshold is showing always around -116 and i dont think mine is a perfect environment for interference. i use omnitik's in different locations and sxt connected to them or sxt to sxt point to point.
2. Distances are variable for different stations but in the pictures below there are 4 sxt connected to a omnitik. 3 of them 300m away and one about 800m.
3. I have tried hw protection but i dont use it right now because i haven't seen any improvement by using it. i read somewhere in another topic mikrotik to mikrotik devices use hw protection by themselfs.
4. I dont use preamble mode short on both sides maybe i will try that too if will have any improvement in this or other situations.
5. Nstreme i have checked poolling and Disable CSMA
6. Omnitik max power is 26dBm

After reading other topics and mikrotik manual and wiki i tried a couple of things trying to achieve maximum performance and stability without disconnecting. Nstreme pooling and csma disabled.
1. Tried rising the noise floor threshold until i got good Tx rate and stability. Rising noise floor threshold too much will result in poor rate selection because of lower SNR. I set noise floor threshold to -103 in this location.
2. Tried various of other options in advanced wireless interface settings like hw retries, disconnect timeout and on fail retry but none of them did help with disconnection issue. After searching more online and in other topics read that mikrotik work better on QAM16 modulation. First i tried wireless N only but sxt keept disconnecting randomly from registration table with not pooled for too long message in log. Then i selected only QAM16 in suported rates and maybe resolved the disconnecting issue. since sxt uptime is more than 12h now.

Dont want to arrive at a conclusion too fast but maybe nstreme disconnects on modulation different of QAM16 or just when modulation is swiched.

Now i have 30-40 M on single tcp connection while on Nv2 was 5-7 M and from node to node with active traffic was even worse.

Elliot can i ask you why use nstreme (exact size - 3600+). what is the purpose to it? i was thinking what could fix the disconnecting issue

Sure you can. I'm not a guru in terms of Mikrotik devices but over last year I've only one job - to make link as good as possible in heavy noise/interference environment. I've tweaked over 1000 antennas so I know a few things that works etc. Exact size is basically what size of frames will Mikrotik send to other side. "Exact size" does that Mikrotik will send 1 frame with exactly 0-4000 packets, if there's not enough packets he will wait. "Dynamic size" means that Mikrotik will stack packets into different sized frames depending on his (Mikrotik/Processor) algorithm. From my experience "exact size" will give you the best throughput with the lowest latency and most importantly ...almost no ping/packet loss. Best case for me is between (3200-4000) that!s why I've told you to set in on "exact size - 3600+". If you want another tips tell me more about your setup and in what kind of environment does it operate, also what's the distances, how many clients, how many channels free (or not free) etc.

As for your disconnecting issues I've experienced it with Nstreme only once or twice. Key problems that you need to check are:
1. what kind of interference/obstacles are there in the area of your clients and/or APs
2. how far away are your other AP (They could create interference/noise for themselfs)
3. do you use "ap to clients protection" on APs and "client protection" on clients + you can you HW protection on clients as well
4. preamble mode - short on both sides can work magic sometimes
5. also in Nstreme do you have checked Polling and Disable CSMA and Nstreme ? if not ...you should
6. What kind of antena and power do you use ?

I suspect that you disconnections problem could be cause by couple of things
A: incorrect alignment (do they have MIMO?)
B: incorrect setting of Tx Power (clients and or/AP are oversaturated, overpowered on short distances)
C: incorrect choice of channel + wrong channel width

anyway I'm glad I could help. Please do let me know how did you resolve or didn't resolve this issues. Have a good one mate and don't forget to test and tweak in real environment because it's the only way how you can setup your routerboard exactly to fit your needs.

Also if you use some kind of security profile do not use TKIP and only AES.

hi Elliot
can you explaint how to use "ap to clients protection" on APs and "client protection" on clients + you can you HW protection on clients ?
and preamble mode - short on both sides can work magic sometimes
I have also nstreme link and disconnected many time. using nv2 there is no problem but bad throughput and latency. Nstreme is best but has disconnection problems.
Im using 34dbi dish and netmetalAC for 16km link.
thanks