Table of content: Executive summary What is a BCOP? Introduction and incentives Size of end-user prefix assignment: /48, /56 or something else? 4.1. Numbering the WAN link (interconnection between the network and the end-user CPE) 4.1.1. /64 prefix from a dedicated pool of IPv6 prefixes 4.1.2. Unnumbered 4.1.3. ULA 4.1.4. /64 prefix out of the IPv6 prefix assigned to the end-user 4.1.5. Summary 4.