Low Uplink Capacity

Hi there, how can i increase uplink capacity where my link is about  RSSI 67/68 ,SNR 27/28, MCS 11-13/(9-12), link quality 100%?

l tried with frequences for hours but link capacity remains mostly 40-60%. Changed port speed to manual 100 full.

additional info:
4.45 km, e force 110, 20 Mhz,  5670, 58/35 Mbps, v 2.5.2

My problem: Poor throughput during pc-pc sharing. min 2Mbps Max 30 Mbps (fluctuating)

How can i resolve low link capacity and fluctuation  of throughput?

1. When you use ACS or use the SA to look at the channel 5670, how clean is it? Have you looked at both sides of the link? Can you post a screenshot of both sides?

2. You should not need to manually/force the ethernet interface to 100/Full... you should verify that you're not having speed/duplex mis-match issues between devices and ensure that all of your RJ45 terminations are of high-quality and pre-tested.

3. What wireless mode are you using TDD? TDD-PTP? ePTP? and what framing? flexible? 2.5ms or 5ms?

4. You say you're using PC to PC sharing... file sharing via SMB? What are speeds like when you copy one big file.. e.g. like a 2GB movie... vs. many little files? When you simply connect an ethernet cable between the two PC's, what speeds do you see when you try to copy a big file vs. a lot of little files?

5. What does the built in radio to radio speed test results give you?

3 Likes

Hi,

This is our same problem

http://community.cambiumnetworks.com/t5/ePMP-1000/ePMP-1000-Good-Speed-in-DOS-Ping-but-Low-Throuput-in-Real/m-p/47778#M4309

.

Nobody can't help us yet.

Hello rahmandoost,

If you have the same issue please try to answer reasonable questions from Eric Ozrelic.

Thank you.

Hey Eric

Thanks for your reply.

ACS selected 5.8 freq which results poorer than this channel.

TOday i jumped  20 Mhz to 40 Mhz(5415 MHz). RSSI 66/67, Built in UI Speed 96/61 Mbps.
But real throughput remains same as it was in 20 MHz.

TDD-PTP mode. flexible, framing as default.

I shared files with 1 gb movie file to each other. I got Down 3/up 1.5 MB
But sharing Up/Down at a time i got 4 & 3 MB.

90% MCS @ Down & 65 % in UP (B)

I'll upload screen shot ASAP.

It looks like you have interference on your channel on SM side.

I would be really appreciate it if you could run eDetect Tool (Tools -> eDetect) to find interference source.

Also you can try to use 10 MHz channel it will have higher spectrum density.

Thank you.

1 Like

Thanks Fedor,


I ran eDetect every time i select any frequency. I didn't see any issue.
I'll try to change to 10 Mhz by tomorrow.

I didn't try 10 Mhz coz my client need at least 42 Mbps real throughput for monitoring  7 IP cam.

My main problem I didn't get real throughput as it shown in UI.

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Interference can be on 5 MHz up or down behind your channel or it can be interference type which eDetect can not identify.

What about Statistic(Monitor->Performance)? Which MSCs are used on DL and UL?

Also attach please screenshot with Wireless Statistics for UL and DL.

Thank you.

I Also attach detail screenshot of both side. Hope it will help u to resolve this issue.

A few things that I see...

1. Exactly what ePMP radios are you using? The reason I ask is for a link this short, assuming it's line of sight, if you were using a Force 110, or even Force 180, I would expect a much better signal and much higher SnR. If you're using the older integrated radios, then I would swap them out for the above mentioned radios.

2. I would go back to a 20MHz or even 10MHz channel width if I were you. Your SnR and modulation should improve and your error rate should decrease.

3. On a2.jpg, and a6.jpg, there are quite a lot of 'Error drop packets', 'Capacity drop packets' and a rather large amount of 'Retransmission packets'. These are usually caused by interference.

4. Again, on a2.jpg, and a6.jpg I see quite a bit of  multicast and broadcast traffic going over the link. Are you intending to send this kind of traffic over the link?

5. Are you using any MIR or QoS settings on either end of the link? Can you send a screen shot of what you have setup?

6. You might want to try to lock the highest MCS on each side based upon the highest successful packets sent %... e.g. MCS12 on one side, and MCS12 or MCS11 on the other side.

7. Have you tried ePTP mode? NOTE! You will not be able to set MIR/QoS or be able to lock the MCS rate with ePTP mode.

1 Like

Eric provided comprehensive recommendations.

Acifcwn, please follow them.

Only thing that I would like to add is that you should determine interference source.

It could be not only wi-fi devices, it could be FM-transmitters, high-power cables, etc.

They may affect your device on every channel. So you should find root cause and try to isolate it.

Thank you.