Low througput with simple p2p SXT link

RouterOS Wireless Networking
1

Hi,
I made a testing environment with 2x SXT LITE5.

Setup:
Distance ~4m.
I lowered the TX power.
Each SXT has a windows pc (win7 and :sunglasses: directly connected to it.

Results (pc to pc over a gbit switch):

C:\iperf>iperf -c 192.168.0.16 -w 256k -l 256k
------------------------------------------------------------
Client connecting to 192.168.0.16, TCP port 5001
TCP window size:  256 KByte
------------------------------------------------------------
[  3] local 192.168.0.32 port 53372 connected with 192.168.0.16 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  1.07 GBytes   916 Mbits/sec

C:\iperf>iperf -c 192.168.0.16 -w 256k -l 256k -d
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size:  256 KByte
------------------------------------------------------------
------------------------------------------------------------
Client connecting to 192.168.0.16, TCP port 5001
TCP window size:  256 KByte
------------------------------------------------------------
[  4] local 192.168.0.32 port 53477 connected with 192.168.0.16 port 5001
[  5] local 192.168.0.32 port 5001 connected with 192.168.0.16 port 49394
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec   724 MBytes   607 Mbits/sec
[  5]  0.0-10.1 sec   723 MBytes   600 Mbits/sec

Results over the SXT link:

SXT to SXT UDP bandwidth test yields ~98MBit each way and bi directional. TCP didn’t make sense cause it would peg the SXT cpu at 100%.

Iperf:

C:\iperf>iperf -c 192.168.0.16
------------------------------------------------------------
Client connecting to 192.168.0.16, TCP port 5001
TCP window size: 64.0 KByte (default)
------------------------------------------------------------
[  3] local 192.168.0.32 port 51727 connected with 192.168.0.16 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  58.9 MBytes  49.2 Mbits/sec




C:\iperf>iperf -c 192.168.0.16 -d
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 64.0 KByte (default)
------------------------------------------------------------
------------------------------------------------------------
Client connecting to 192.168.0.16, TCP port 5001
TCP window size: 64.0 KByte (default)
------------------------------------------------------------
[  4] local 192.168.0.32 port 51871 connected with 192.168.0.16 port 5001
[  5] local 192.168.0.32 port 5001 connected with 192.168.0.16 port 49387
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  43.5 MBytes  36.4 Mbits/sec
[  5]  0.0-10.1 sec  42.9 MBytes  35.5 Mbits/sec

Very low.
Weird thing is that file copy pc to pc over SXT yields better throughput:

I can get ~85Mbits in each direction, but full duplex only 53/53Mbits.
The SXT cpu is fine (~40% usage) and I have no idea what to do or how to test.
Mikrotik bandwidth test from PC to PC gives crap numbers, much lower than real tests or even iperf.

Any ideas what could be wrong?

2

What speeds are showing in Wireless Registrations ?

Did you make sure both chains were enabled ?


Nick.

3

It connected at 300/300 signal -45 if I recall correctly, it was a few days ago.

UDP SXT to SXT was over 100/100Mbit full duplex.
UDP SXT to SXT one way was up to 210Mbit.

I’ll retest and document better :slight_smile: