A5 - low speed - no auto channel

Hello,

my A5c with 2 antenas 90deg, both facing other direction is lately suffering from very low speed at pek (max 120MBit in 40MHz). Some time ago it could be more than 200MBit…
Clients - 21.
PHy rates are all around 400/400…
Auto Chanel is not working… maybe something is broken?

Edit: in new beta software is added split 75/25 - and now I can achieve 200MBits. But i Would like to have split 80/20 or even 85/15

  1. It sounds like the issue hasn’t really been resolved, 200 Mbps is what you were seeing as performance before 75/25, that you are back there only means the issue is being covered up my more TX time by your AP. I would start checking for issues.

  2. Going above a 75/25 split is not a good idea, most of your customer’s traffic is TCP, which requires a steady 2 way traffic. While the ACK packets from your customers are small and are not as numerous as what they are downloading, Acknowledge Packets are very important to the operation of TCP, if the server doesn’t get a ACK packet soon enough to may waste bandwidth and begin resending packets it’s already sent, or at the least it will delay the sending of more packets therby hurting the overall throughput of your customers. VOIP also can be very negatively impacted by too small of an upload window, while it would be consistent in happening, it would easily become swamped with other traffic causing bottlenecks that would hinder the real time needs of VOIP or any service that your customers tried to use that required upload bandwidth…

How should I start checking for issues?

You mentioned that most of your customers were at full modulation, are there some that are below full modulation or might have jumps in modulation? You might see the drops in modulation when a customer is actually pushing traffic.

From there, I would look at the customers who have lower modulation and try to see what could be bugging them, noise, low RX power, issues with the Chains being significantly mismatched (alignment) the normal stuff.

Next up would be turning off various Auto portions of the AP to see if something is acting up there, but that might take a long time to diagnose. The first one I would try is Auto AGC, because it’s the simplest to work with. There are manual pages I can link you to if you get to that point.