Additionally, {HEAD ~ one microprocessor} could be shared to handle multiple DID trunk or {TAIL ~ E&M tie lines} 
shared to handle
Additionally , { HEAD ~ one microprocessor } could be shared to handle multiple DID trunk or { TAIL ~ E&M tie lines }
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL