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