It will then connect the incoming CO side of the DID line or {HEAD ~ E&M tie line} through to {TAIL ~ the PBX} and thus to the VMS 
It will then connect the incoming CO side of the DID line or { HEAD ~ E&M tie line } through to { TAIL ~ the PBX } and thus to the VMS
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH