Building an SD-WAN network between CPE devices

To transfer traffic, you need to build an SD-WAN network between CPE devices using links that are established on top of the underlay network. CPE devices establish links from all available SD-WAN interfaces of the WAN type. The links are unidirectional. This means that when establishing a link from CPE 1 to CPE 2, a link is automatically established also from CPE 2 to CPE 1. Before building an SD-WAN network, you must ensure connectivity between CPE devices.

Links are established based on the roles that you assign to CPE devices. You can assign the SD-WAN Gateway role or the standard CPE device role to a CPE device. SD-WAN Gateways establish links with all standard CPE devices and other SD-WAN Gateways. Standard CPE devices establish links only with SD-WAN Gateways. By default, all CPE devices have the standard CPE device role.

If you want a link to be established between two standard CPE devices, you need to assign the same topology tag to these standard CPE devices. You can also make a standard CPE device a transit device to allow other CPE devices to establish links through that CPE device.

The links between CPE devices form a topology. The following topologies are the most commonly used in Kaspersky SD-WAN:

• In a Hub-and-Spoke topology, links between CPE devices are established through SD-WAN gateways.
• In Full-Mesh and Partial-Mesh topologies, links between CPE devices are established directly, or some links are established directly, while others are established through SD-WAN gateways.

Within the SD-WAN network, traffic between CPE devices can take multiple paths. The paths go through the links between CPE devices. The totality of all possible paths between two CPE devices is called a segment. The segment source CPE device can distribute the traffic bound to the segment destination CPE device across multiple paths. One segment can contain 2 to 16 paths.

The following path types are supported:

• Auto-SPF (Shortest-Path Forwarding) is a path that is automatically calculated by the controller. You can forward traffic along Auto-SPF paths in two modes:
  • In Active/Active mode, multiple Auto-SPF paths are used simultaneously to forward traffic between CPE devices.
  • In Active/Standby mode, one Auto-SPF path with the lowest cost is used to forward traffic between CPE devices. If the Auto-SPF path being used becomes unavailable, the Auto-SPF path with the next lowest cost is used. The path cost is calculated by adding up the cost of every link traversed by the path. You can manually specify link cost.

  You can configure the traffic forwarding mode along Auto-SPF paths when configuring the paths.

• Auto-TE (Traffic Engineering) is a path automatically calculated by the controller, taking into account the threshold constraints you specified.
• Manual-TE is a path that you manually created. When creating a Manual-TE path, specify the links that the path passes through on the way from the segment source CPE device to the segment destination CPE device.