Help with poor performance on NSG100/500Mb cable broadband


I have an NSG100 protecting my local network and this is connected to a Virgin Media Business cable router (500Mb service). The Virgin router is in modem only mode as i have static IP addresses. The NSG has a single static IP address on WAN2 (connected via RJ45) and this should be connected at 1Gb. 
The internal network is running on a gigabit backbone with my gigabit switch connecting directly into the NSG100. my servers are connected to the switch directly via teamed nics so each server has 4 nics connected at 1Gbe each.
The NSG100 has all security features turned on to maximize protection.
When I run a speed test on one of my servers i am only seeing 160Mb down at best. if i turn off the zyxel security features it will maybe improve by 2-5Mb. 
If I plug my laptop directly into the Virgin router and set a static ip then my laptop shows more like 350Mb download.
What am i doing wrong with the NSG100 that the speed is so much lower through it? I cant seem to find a way to check what speed the link between the NSG100 and the Virgin router is being negotiated at to rule this out. I find it hard to believe that the NSG100 overheads can lose me 200Mbps.
I ordered the NSG100 as it was cloud managed and it is capable of 450Mbps throughput according to the datasheet so should be fine with my 500Mb cable service.
I need some help here as I'm having issues with remote working, streaming etc due to the low speeds

All Replies

  • Nebula_ChrisNebula_Chris Zyxel Official Agent Posts: 304  mod
    Hello @Gareth
    The throughput on datasheet is the UDP speed, there is the asterisk in the bottom which has explain SPI firewall and VPN throughput is the UDP others are TCP, so the result which you get for 160Mbps is pretty close with the document.
    You mention about when disable security features only get 2 to 3 Mbps improved, it should be better can you try again when there is not much people using the network and turn off the App patrol this time.
    If you plan to get better throughput with security function then will suggest to use NSG200.
    Can you share more detail about your streaming application, is the IPTV?

  • Hi Chris

    160Mbps on a 500Mbps connection does not seem right though even allowing for the fact that during the pandemic I was only getting 350Mbps directly connected to the Virgin media router but this is still well above the 160Mbps i am getting through the NSG100, even with the security settings turned off. 
    The Streaming app im using is Plex. I do use IPTV but dont seem to have many issues with that as it runs on port 80
  • I was looking at the NSG200 when i purchased the NSG100 but was told for a 500Mb line the NSG100 would be fine. Is it possible to bond WAN1 and WAN2 so i can use double the bandwidth?
  • out of interest, what kind of throughput would i expect to see on the NSG200? I see that the SPI supports 1200Mbps if I'm reading it correctly. What would I be able to expect with all security services turned on and app monitoring?
  • Nebula_ChrisNebula_Chris Zyxel Official Agent Posts: 304  mod
    edited October 28, 2020 11:14AM
    Sorry NSG cannot bond 2 WAN interface together.
    Are you using Speedtest (Ookla) or other test vendor? In my local environment can reach to 230Mbps (NSG100 without security off), is possible for you to use different laptop/PC for testing? Since it's relevant to test device's hardware capability. If still get the same result then please enable the support request in Nebula, Help page also provide me your Org. and site name. :)

  • Nebula_ChrisNebula_Chris Zyxel Official Agent Posts: 304  mod
    edited October 28, 2020 1:38PM
    NSG200 with security feature off (1G connection in our office) the speedtest result is around 460 to 492 Mbps.

    my laptop spec.
    CPU: i5-6200
    RAM: 12GB

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