需要在 客户驻地（Customer Premises，CP） 路由器中嵌入 UPnP IGD-PCP IWF，以允许在其中在LAN侧使用UPnP IGBT并且在CP路由器的外部侧使用PCP的环境中进行透明NAT控制。

Port Control Protocol (PCP) is a computer networking protocol that allows hosts on IPv4 or IPv6 networks to control how the incoming IPv4 or IPv6 packets are translated and forwarded by an upstream router that performs network address translation (NAT) or packet filtering.

The Port Control Protocol allows an IPv6 or IPv4 host to control how incoming IPv6 or IPv4 packets are translated and forwarded by a Network Address Translator (NAT) or simple firewall, and also allows a host to optimize its outgoing NAT keepalive messages. 端口控制协议允许IPv6或IPv4主机控制通过网络地址转换器（NAT）或简单防火墙转换和转发传入IPv6或IPv4数据包的方式，还允许主机优化其传出NAT keepalive消息。

本文件规定了通用即插即用（UPnP）互联网网关设备-端口控制协议互通功能（IGD-PCP IWF）的行为。 UPnP IGD-PCP IWF需要嵌入到客户场所（CP）路由器中，以便在局域网侧使用UPnP IGD，CP路由器外部使用PCP的环境中实现透明的NAT控制。

PCP is designed to be implemented in the context of Carrier-Grade NATs (CGNs) and small NATs (e.g., residential NATs), as well as with dual-stack and IPv6-only Customer Premises Equipment (CPE) routers, and all of the currently known transition scenarios towards IPv6-only CPE routers. PCP allows hosts to operate servers for a long time (e.g., a ...

事实上，在使用PCP为传入连接创建显式映射之后，需要向远程主机通知传入连接的IP地址、协议和端口号，以便到达DS Lite CGN后面托管的服务。

在“客户端”（ISP订阅者PC）上，负责发送PCP MAP请求的是什么？ 操作系统、应用程序还是某个包装程序？ （也就是说，我应该在哪里寻找“支持PCP”？ ） 目前，每个程序都会自行发送这样的请求。 还有一些独立的工具可用于发送映射请求（例如 upnpc 或 natpmpc）。

2011年7月6日 · The Port Control Protocol allows an IPv6 or IPv4 host to control how incoming IPv6 or IPv4 packets are translated and forwarded by a network address translator (NAT) or simple firewall, and also allows a host to optimize its outgoing NAT keepalive messages.

2012年11月21日 · This error MUST only be returned for: * MAP requests that included the PREFER_FAILURE Option (normal MAP requests will return an available external port); * MAP requests for the SCTP protocol (PREFER_FAILURE is implied); * PEER requests. See Section 13.2 of [RFC6887] for processing details.

Pytorch implementation of our Partially Convex Potential Maps. The model constructs partially monotone transport maps between probability measures as gradients of partially input convex …