{HEAD ~ The OLT} comprises {TAIL ~ an ingress module}, egress module and a network processor 
comprises
{ HEAD ~ The OLT } comprises { TAIL ~ an ingress module } , egress module and a network processor
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH