PCP Working Group F. Dupont
Internet-Draft Internet Systems Consortium
Intended status: Standards Track T. Tsou
Expires: October 25, 2013 Huawei Technologies
J. Qin
ZTE Corporation
M. Wasserman
Painless Security
D. Zhang
Huawei
April 23, 2013
The Port Control Protocol in Dual-Stack Lite environments
draft-dupont-pcp-dslite-05
Abstract
This document specifies the so-called "plain mode" for the use of the
Port Control Protocol (PCP) in Dual-Stack Lite (DS-Lite)
environments.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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This Internet-Draft will expire on October 25, 2013.
Copyright Notice
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
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Internet-Draft PCP DS-Lite April 2013
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1. Introduction
Dual-Stack Lite (DS-Lite, [RFC6333]) is a technology which enables a
broadband service provider to share IPv4 addresses among customers by
combining two well-known technologies: IP in IP (IPv4-in-IPv6) and
Network Address Translation (NAT).
Typically, the home gateway embeds a Basic Bridging BroadBand (B4)
capability that encapsulates IPv4 traffic into a IPv6 tunnel to the
carrier-grade NAT, named the Address Family Transition Router (AFTR).
AFTRs are run by service providers.
The Port Control Protocol (PCP, [I-D.ietf-pcp-base] allows customer
applications to create mappings in a NAT for new inbound
communications destined to machines located behind a NAT. In a DS-
Lite environment, PCP servers control AFTR devices.
Two different modes of operations have been proposed: the plain and
the encapsulation modes. This document recommends use of the plain
mode.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
2. Plain Mode
In the plain mode the B4, the customer end-point of the DS-Lite IPv6
tunnel, implements a PCP proxy ([I-D.ietf-pcp-proxy]) function and
uses UDP over IPv6 with the AFTR to send PCP requests and receive PCP
responses.
The B4 MUST source PCP requests with the IPv6 address of its DS-Lite
tunnel end-point and MUST use a THIRD PARTY option either empty or
carrying the IPv4 internal address of the mappings.
In the plain mode the PCP discovery ([I-D.ietf-pcp-base] section 7.1
"General PCP Client: Generating a Request") is changed into:
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1. if a PCP server is configured (e.g., in a configuration file or
via DHCPv6), that single configuration source is used as the list
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