Internet Speed Slow Down after connecting to VPN

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Joined: Sat Sep 22, 2018 10:26 pm

Post by sachin1 » Sat Sep 22, 2018 10:49 pm
Hello Viscosity Team,

We are using Viscosity VPN and problem is after connecting to VPN, internet speed slows down but shows connected. Speed before VPN connection is 40 MBPS, after connection it is 100 KBPS.

Can you please help - what settings to change?
1. OS: MAC
2. Internet Connection: Airtel

Please note that when I connect VPN to other internet service provider (my mobile hotspot or office network,), it works fine.
I suspect specific port settings issues with my Airtel service provider. I discussed with them, but they don't have clue.
Please share your support.



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Post by James » Tue Sep 25, 2018 12:09 pm
Hi Sachin,

If you're getting decent performance when connecting to your VPN server from one ISP, but not when connecting to the same VPN server from a different location/ISP, then I recommend checking the following:

1. Check whether your ISP is throttling or shaping VPN connections. Sadly some engage in this behaviour. Often changing the VPN server to use a non-standard port number is enough to avoid throttling. Otherwise you could also look into using Viscosity's obfuscation support.

2. Your internet connection may use a lower MTU. If the VPN connection is set to use a higher MTU this can cause slowness and packet loss (often web pages loaded through a connection with this problem may appear to hang loading, or partially load). You can try lowering the MTU settings client side, however I recommend getting in touch with your VPN Provider or IT administrator in the first instance to discuss the problem.

3. Your VPN Provider may have poor backbone links to your ISP's network. You may want to try testing the speed by attempting to download a file directly from the same network as where the VPN server is located (but not through the VPN connection) to see if it's slow. Or try connecting to a completely different VPN server.

4. Your modem/router may be causing the slowness. Try rebooting it, firmware updating it, or temporarily trying different hardware to see if the slowness persists.

James Bekkema
Viscosity Developer

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