SXT 5ac - Perfect Link but low bandwidth

RouterOS Wireless Networking
1

Hello,
I bought some SXT 5 ac to try the new AC protocol.

I updated them to 6.21.1.

Here’s my first SXT 5 ac link:
sxt1_ac.jpg
Even if CCQ is 100%, signal is good (less than 1km link), the max throughput is about 105Mbps using these settings:

Band: 5GHz-only-N
Channel Width: 20/40MHz Ce
Protocol: nstreme

Using 5GHz-only-AC the speed is lower. Using nv2 or 802.11 is low both on AC or N.

I measured the throughput using iperf with two i7 laptops and using UDP bandwidth test between them, almost same result.

Do you have any advice for me?

2

in my experience with AC, low throughput is the result of not clean frequency channel.
try to scan air and change to free channel. or even better to set to superchannel and go to ~5900

3

But why CCQ 100%? :open_mouth:

4

try to change to nv2 or 802.11 and you will see why :slight_smile:

5

I changed to nv2 and 802.11 and the speed is lower, and either is CCQ. :frowning:
I switched frequencies during the night and I found a good 80MHz channel in AC. Speed is about 220Mbps both on upload and download, which is very good, using nstreme. Using nv2 or 802.11 I can reach only 95Mbps using nv2 and 150 using 802.11.

Using nstreme I have some “extensive data loss”:
extensive.jpg
But signal is very good, and CCQ is about 94-99%…

6

IMO extensive data loss is related to nstreme. thats why i am not using it. nv2 is the way :slight_smile:

7

Nstreme is usually causing too many poll timeouts… not extensive data loss IMO. NV2 is the way in place where you dont have more than 1 link in a chain, otherwise you will see low TCP connection throughput (single or multiple connections)

Switched to nstreme from nv2 on some links and from 10Mbps single or 20Mbps multiple TCP connections now getting over 50Mbps with 1 connection. No extensive data loss noticed. Dual chain N links and 40MHz single chain. Did not test on AC.

8

I don’t argue with you about wireless debug messages. But i a few months ago i tried to optimize wireless networks and played with protocols. With nstreme i got extensive data loss, the same was with plain 802.11N. This wasnt happened with nv2.

It could be that in the p2mp mode tcp throughput is related to protocol, But bigger influence to throughput is clean air or not.
I have to test it.
I will post results here

9

Its just my experience and my opinion, I am not saying it cannot be.. :slight_smile: try to setup nstreme like described here, I have no issue with it:http://forum.mikrotik.com/t/nstreme-over-n-40mhz-dual-chain-links-solved/75445/1

10

Look to my linktest here publisched.
http://www.wirelessinfo.be/index.php/linktesten/sxtacpages/nv2-500-eceee

You can copy and paste my configuration and try what result you have.

Let me now how it was