Sonicwall Global VPN Client connected the Internet speed slow.

To disable Receive Segment Coalescing (RSC) on a network adapter, you can use the PowerShell command Disable-NetAdapterRsc:

Open an admin command prompt window

Use the command powershell Get-NetAdapter to get your network adapter name

Use the command powershell Disable-NetAdapterRsc -Name ADAPTER_NAME_FROM_BEFORE to disable RSC for your network adapter

Use the command powershell Get-NetAdapterRsc to verify that RSC is disabled for IPv4 and IPv6

You can also disable RSC globally using the command netsh int tcp set global rsc=disabled. This command requires an elevated command prompt.

RSC combines multiple packets received within the same interrupt period into a single large packet. This reduces the number of processor cycles used and the processing overhead for incoming packets.

RSC is recommended to be disabled when running latency sensitive traffic.