The adapters are intended to be used for calls coming into {HEAD ~ a PBX} on {TAIL ~ a DID trunk} or E&M tie line 
The adapters are intended to be used for calls coming into { HEAD ~ a PBX } on { TAIL ~ a DID trunk } or E&M tie line
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH