{HEAD ~ The called extension number}, as it is dial pulsed to {TAIL ~ the PBX} by the Central Office or sent on an E&M tie line as dial pulse or DTMF, is monitored and accumulated by the adapter 
{ HEAD ~ The called extension number } , as it is dial pulsed to { TAIL ~ the PBX } by the Central Office or sent on an E&M tie line as dial pulse or DTMF , is monitored and accumulated by the adapter
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH