File transfer over SSL VPn extremely slow (USG FLEX 500)

D2IT Posts: 13
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Hello, we have a USG FLEX 500, when we connect through SSL VPN, the speed of transferring files from a Windows file server to a Windows machine is extremely slow, reaching an average of 500Kbps, taking approximately 50 minutes to transfer one 179Mb file. I emphasize that there is no bandwidth control configured on the firewall, and that we have 2 internet links of 100Mbps each. We tested transferring the same file through L2TP VPN, and the speed was much higher than through SSLVPN, but we did not specifically make this change from SSLVPN to L2TP.

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  • Zyxel_Jeff
    Zyxel_Jeff Posts: 1,099  Zyxel Employee
    First Anniversary 10 Comments Friend Collector First Answer

    Hi @D2IT

    The quality of transmission for the remote VPN is dependent on the internet connection used by the remote user. Therefore, we recommend using the SSL VPN client to ping the internal LAN clients and check for frequent occurrence of ping drop symptoms. If such symptoms persist, it suggests that the SSL VPN client's connection may not be optimal. Additionally, concerning the screenshot you provided, it appears that you attempted to transmit 3053 items. Would it be more efficient to transmit fewer files at a time? If you switch to an L2TP VPN connection, would that be preferable for you? Thanks.

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