SSL-VPN Limitations

TTpD Posts: 6
First Comment
edited April 2021 in Security
We own a USG20-VPN, firmware version v4.33_ABAQ.0 and we are running a SSL_VPN, but is really slow, even with 1 or 2 concurrent users, obviously each with their different credentials.

On a "Single ssl-vpn connection" between a Gigabit-FTTH and a 20Mb/s link, the maximum download rate is 700MB per Hour, which is approximately 1.5Mb/s: this is almost unusable.

Every alternative remote connection works fine and faster: Chrome Remote Desktop, Teamviewer, Anydesk and so on, so it seems a firewall's issue.

  • How many concurrent users can, a USG20_VPN, manage without dropping connection or performing poorly?

All Replies

  • Zyxel_Stanley
    Zyxel_Stanley Posts: 1,366  Zyxel Employee
    First Anniversary 10 Comments Friend Collector First Answer

    Hi @TTpD

    The default SSL VPN tunnel can establish for 5 tunnels, and it can extend up to 15 tunnels by license.

    If you have more throughput requirement in VPN tunnel , or you can consider to deploy L2TP VPN tunnel in your environment instead.

  • TTpD
    TTpD Posts: 6
    First Comment
    edited June 2020
    1. do you consider 1.5Mb/s a decent performance just for 2 connections? It is quite limiting considering we are not using 5 concurrent connections!
    2. Is maybe L2tp/Ipsec better performing?
    3. We do not need more connections, just good speed

  • CHS
    CHS Posts: 177  Master Member
    First Anniversary 10 Comments Friend Collector First Answer

    I built L2TP VPN tunnel to my USG60W and test performance by speedtest.

    I get download/upload= 80/40 Mbps.

    The performance is better than SSL VPN tunnel.

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