What is VPN and how does it work?

VPNs can provide highly secure connections that let remote employees connect with each other and with the tools they need to work

by The AT&T Business Editorial Team




The essential VPN


IPsec versus MPLS

While there are several types of VPNs, enterprises generally use either an Internet Protocol security (IPsec) or Multiprotocol Label Switching (MPLS) VPN to connect their remote and mobile employees to data, apps, and other corporate resources. The terms “IPsec” and “MPLS” indicate the way each type of VPN transmits data.

The primary differences between IPsec and MPLS are related to the networks they run over. IPsec connects sites using public Internet transport, which is made of interconnected networks run by different carriers. MPLS connects sites using a single carrier’s MPLS network. The carrier has management control of the network, including the ability to enforce quality-of-service policies on traffic flows. MPLS VPNs partition each customer’s traffic from the others to keep it private across the infrastructure.

Which is right for you?


  • The size of the sites to be connected
  • How much bandwidth you need at that site
  • Your performance reliability requirements for that site
  • Your WAN connectivity budget for the site


To learn more about VPNs and the benefits they can bring to your business, visit the AT&T VPN services.