SOAP over UDP
The CXF SOAP binding supports the use of the SOAP over UDP specification URL's for transporting SOAP messages over UDP. Just using "soap.udp" as the scheme part of the UDP URL (instead of just "udp") will enable the SOAP over UDP support.
The main difference between using the pure UDP CXF transport and the SOAP over UDP support is that SOAP over UDP requires the use of WS-Addressing headers whereas the pure CXF UDP transport does not. The WS-Addressing header can add significant size to the SOAP messages. With UDP limiting the size of the packets to under 64K, that can be significant.