NEC NEC NEC NEC This document describes a new Port Control Protocol (PCP) option called the THIRD_PARTY_ID option. It is designed to be used together with the THIRD_PARTY option specified in RFC 6887. The THIRD_PARTY_ID option serves to identify a third party in situations where a third party's IP address contained in the THIRD_PARTY option does not provide sufficient information to create requested mappings in a PCP-controlled device.