NXC2500 Wireless Internet Speed Slow

danielson81 Posts: 8
First Comment
edited August 26 in WirelessLAN


We have a NXC2500 and several NWA 5121-NI access points.

We have set up as per these instructions:


Basically, two separate networks, one “Office” one and one for “Guests”

Our setup goes AP >> HP POE Switch >> NXC2500 >> GE1/P1 to our LAN and GE2/P3  to our DMZ (ie guest network). 

The issue is the actual internet speed is barely reaching 20MB, despite us having a 200MB leased line.

But, most devices are connecting wirelessly at around 70MB+,  ok I don’t expect 144MB but surely it should be faster than 20MB?

I have played around with Wireless Channels to no avail, and changed the AP SSIDS to no security to rule that out.

Also if you plug a laptop in directly to the HP POE Switch, it achieves speeds that match our internet connection.

Does anyone have any ideas?



  • Zyxel_Freda
    Zyxel_Freda Posts: 397
    25 Answers First Comment Friend Collector Third Anniversary
     Zyxel Employee
    Hi @danielson81 ,
    When the Cipher type select to TKIP, the link speed can only up to 54Mbps and the actual wireless speed might be only about 50%-70% of 54Mbps based on the test environment status.
    So, based on your security setting described in the document, it might be the reason of low speed. Would you use the WPA2-AES to test again and share the configuration of the NXC2500 for us to check detail settings?
    BTW, because the new firmware version doesn't support cipher type 'TKIP', may I know what version you use on the NXC2500 now? If there's no specific concern, would you upgrade to the last firmware version and test again?
    Here is the last firmware download link for your reference.
    If you still have some machines need to use TKIP, you can select WPA2-mix with cipher type 'Auto' in new firmware.
  • Thanks for your response, the security profile is setup like this:

    We have the latest firmware.

    I am next to the access point (that is my phone highlighted)

    My phone got 22MB down and 58mb up on a speed test, but is connected at 144MB. I dont expect 144MB down however would expect slightly higher ! 

  • conf file attached (ive edit the SSID names/passwords, but everything else is the same). 
  • I have just plugged in a new NWA5123-AC and set up a 5G Profile, speed test on phone was 90mb up/down which is a lot better. 
  • Zyxel_Freda
    Zyxel_Freda Posts: 397
    25 Answers First Comment Friend Collector Third Anniversary
     Zyxel Employee
    Hi @danielson81 ,
    Because the 2.4GHz is easier impacted by the interference than 5GHz, the test result of 5GHz would be better than 2.4GHz as your test result. So, if it's possible, it's better to let the users connect on 5GHz to get better performance.
    For the 2.4GHz test, would you check below items for checking the interference status:
    1. Please use wireless scan tool to check if there's any other 2.4GHz signal
    2. It's recommended to lower the channel width to 20MHz to get less interference
    If you still have any problem about the 2.4GHz performance, please help to provide the diagnostic for us to check details.