Reduced bandwith when accessing to Company LAN from outer Internet via USG110

USG_User Posts: 349
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edited May 2021 in Security
We are using an USG110 with latest FW since years. Recently we've changed our ISP from a DSL Provider to a Fiber Provider with a new external IP etc.

Since we've switched we're encountering the following problem:
From our internal Company LAN with different "private" IP zones we got always the full speed of 100 Mbit/s up/dn.
But when accessing from the internet to one of our zones, we have times with full speed and time periods with reduced, very low speed, irrespective whether we'are connected via VPN/RDP, VPN/SMB or diectly via https to a webserver.

external download speed from our server over days

And during time periods of low speed we are not really able to e.g. remotely work from home or download files from our https webserver. The speed is to low for normal work.

Our ISP's opinion is, that this is not his responsibility since the Upload/Download speed from inside our Company is always fine and this is the same way.
But from our point of view there must be an difference whether a TCP connection is initiated from inside the company network or from the internet.

Has anybody any experiences where the USG was responsible for such regular speed drops?

All Replies

  • PeterUK
    PeterUK Posts: 1,669
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    This is likely a ISP issue if you never had this problem before with the DSL line.

  • Zyxel_Jerry
    Zyxel_Jerry Posts: 772
    Zyxel Certified Network Administrator - Security Zyxel Certified Sales Associate 50 Answers 500 Comments
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    1.Are you using single wan or dual wan?
    2.If you're using dual wan, are both wan interface external IP get from the same ISP?
    3.If you’re using single wan, you can try to put a host (PC/Laptop) on the wan2 interface and set as static IP, try to access one of your zones in LAN and check if the symptom occurs, if the symptoms do not occur, the root cause should not be on the device but somewhere else.
  • USG_User
    USG_User Posts: 349
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    Hi Jerry,
    First time we used both WANs and thought we've mistakenly arranged BWM. But since a couple of days we are using single WAN only and WAN2 is not longer connected. But the download bandwith drops when accessing from the internet to our Company LAN still remain.
    It's a great idea to connect a host to WAN2 to try another access way from "extern" to USG. We will give it a try.

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