Split-tunneling is a networking approach that lets a remote user using Remote Access Virtual Private Network (RAVPN) to have specific traffic sent to the internet instead of being sent over the encrypted VPN tunnel.
E.g. – A remote user is using a home network, hotel network or coffee shop to Remote Access VPN (RAVPN) to connect to their works corporate network . The user or VPN subnet with split tunneling enabled can allow the user to send specific traffic such as; access to company file stores, company database servers, company mail servers and other servers on the corporate resources through the RAVPN connection. When the user connects to Internet resources such as Web sites, Personal Webmail, Voice or Video calls, etc.), the connection request can be sent directly out the local gateway provided by the home network, hotel network or coffee shop, thus preventing the traffic from being sent to the corporate network to be redirected to the internet, instead just going directly to the internet.
There are some Advantages of Split-Tunneling can be preventing bottlenecks especially if the user uses Voice/Video calls, where the calls can be severely depredated due to having to pass through the VPN tunnel first.
There are also some disadvantages of Split-Tunneling in that the user now by-passes Corporate security controls that may be in place by the Security team for access to specific sites etc.