The IP Router IPR/S 2.1 connects the KNX bus with the Ethernet network. KNX telegrams can be sent to or received from other devices via the network. The device uses the KNXnet/IP protocol from the KNX Association for communication. This is not compatible with the EIBlib/IP protocol as used for example, by the IP Gateway IG/S 1.1. In older documents and in the ETS 3.0e the KNXnet/IP protocol is also referred to as the EIBnet/IP protocol. Both protocols and specifications are identical.