I heard ISPs, internet service providers, are watching the internet and how we use their services. So for example a big sized download/upload traffic through torrent is being blocked by some ISPs, or if they detects it, they might investigate about the traffic.

Now I use rsync through SSH to send big files (like 600 to 2000 GB weekly) from my PC to my remote placed PC over internet, constantly, just for backing up. I'm concerned if the ISP could notice the high traffic.

Could they? Should I use a VPN on the both of PCs to hide the traffic from ISP? (I don't like to use VPN because it delays the speed if possible)

  • 1
    Well, with VPN you just shift the heavy traffic to type/port SSH to type/port VPN...
    – Tom Yan
    May 9, 2021 at 4:53
  • 4
    Yes, they can detect SSH usage. They can also detect VPN usage. The question is if your ISP does, and if it has any consequence.
    – dirkt
    May 9, 2021 at 4:54
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    Why are you concerned? Why would your ISP care about SSH transfers? They shouldn’t. Torrents are torrents but SSH connections on port 22 are standard. I will say that many public Wi-Fi networks explicitly block SSH connections. But that is not monitoring traffic; some public Wi-Fi networks simply don’t want their free access to be used for stuff like SSH. May 9, 2021 at 4:55
  • so SSH is as safe as VPNs (for ISPs) am I correct? May 9, 2021 at 4:57
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    @pupsozeyde Changing the SSH port is probably unnecessary, as SSH is encrypted anyways. Also it might cause weird behaviour with realtime stuff like Zoom or gaming. But by all means change it if you would like to
    – Compositr
    May 9, 2021 at 5:14

1 Answer 1


The ISP will be able to see the amount of traffic you are sending or receiving regardless of the protocol or encryption that you are using.

If you have a limit let's say 1GB per month on your internet connections through fair use policy it can be enforced in various ways. Usually your data rate will be lowered. In this case it doesn't matter what you use, everything will be "slower".

In some cases ports or protocols or services are blocked completely as you suggest but I haven't experienced that for a while now (at least not with German ISPs, not counting a few exceptions which didn't have anything to do with fair use policy or the prevention of certain services).

  • What ports or protocols are completely blocked in China? That certain western non-compliant big players are blocked (actually throttled) there is a totally different story. We use VPNs anyway. May 9, 2021 at 15:36
  • @ChanganAuto that was just an example, that some involved parties (e.g. countries) might block certain services partly or completely. Bad wording from my part. Sorry. I changed it.
    – Albin
    May 9, 2021 at 15:49
  • Thank you for the correction. +1 May 9, 2021 at 16:08

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