policy based routing (PBR)

The algorithms of classic router concepts are connection-oriented. The router makes a targeted decision about the connection to the next hop. This decision can be based on the destination, traffic, congestion, transmission costs or other criteria.

Policy-based routing (PBR) is different. In this technique, the decision to which router a connection is established is made by predefined policies. Such a policy set must be administratively created, constantly maintained and updated. The policies to be followed by the router may concern the data source, the data packet length, the transport protocol, certain set flags that must be considered, or other criteria. For example, a PBR router may comply with the policy, "If the data packet originates from this data source and must be transmitted to this data sink, then route it to this hop." PBR routers have the ability to reach the destination via multiple connections.