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