Local mode configuration terminates X.25 at the router
interface. The end2end mode configuration allows X.25
signalling and data to operate between two remote X.25
networks, using the router to translate both call control
and data over a TCP/IP network. The gateway mode terminates
X.25 at the router interface, but allows the user to configure
3 message header types at the TCP application layer. These
header values are described in wfIpexMappingMsgHdrType.