The NAS Transparent Path Function (XPATH) allows a calling DTE to request connection to
another DTE without any host system intervention. The connection to the called DTE is
established via a separate call request which is generated by the Control Program. This
feature permits DTE to DTE sessions to be created using the CCU as a pass through control
point. A calling DTE requests XPATH connection by using an INCOMING CALL packet with a
protocol ID of X'55' or by selecting an XPATH POOL macro to control session establishment.
XPATH may be used to initiate DTE to DTE sessions for ITI, BPAD, DSP, QLLC and PSH DTE's.