There are 3 PDAs(Zebra MC9200 scanning handgun) associated with it and they often have trouble sending data to web server. There's no pattern, but when I run netlog on the PDAs and the server, there are lots of TCP retransmission, duplicate, out-of-order. And the PDA eventually cuts the communications.
This started a month ago, but it seems it's getting worse. And when I tested with my laptop connecting to the AP, it shows the same symptom, so I guess the AP.
One thing I noticed in the AP is there are many RX CRC Errors and packet drop. The CRC error rate on RX side is almost 15%.
This is what I have done so far;
- changed cable from AP to switch
- show log in switch, nothing found
- changed with the same model of AP, nothing improved, still CRC errors
- current major settings of the AP
No 5 Ghz, turned off
Power: 18dBm fixed. No Smart (I did this as it shows the error gets less).
Changed antenna from horizontal to vertical (MP-2499-HPA8-01-D
Last thing I may try is to upgrade firmware from 126.96.36.199-004R to 5.9.0-007R.
Any comment is appreciated.