Retrieving the Capabilities of a PCP-controlled Device
draft-boucadair-pcp-capability-00

PCP Working Group                                           M. Boucadair
Internet-Draft                                            France Telecom
Intended status: Standards Track                                R. Penno
Expires: March 21, 2013                                          D. Wing
                                                                   Cisco
                                                      September 17, 2012

         Retrieving the Capabilities of a PCP-controlled Device
                   draft-boucadair-pcp-capability-00

Abstract

   This document extends Port Control Protocol (PCP) with the ability to
   retrieve the capabilities of PCP-controlled device: CAPABILITY
   Option.

Requirements Language

   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].

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on March 21, 2013.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   (http://trustee.ietf.org/license-info) in effect on the date of

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   publication of this document.  Please review these documents
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  CAPABILITY  . . . . . . . . . . . . . . . . . . . . . . . . . . 3
   3.  Security Considerations . . . . . . . . . . . . . . . . . . . . 6
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
   5.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 6
     5.1.  Normative References  . . . . . . . . . . . . . . . . . . . 6
     5.2.  Informative References  . . . . . . . . . . . . . . . . . . 7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 7

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1.  Introduction

   This document extends the base PCP [I-D.ietf-pcp-base] with a new
   feature to discover the capabilities of a PCP-controlled device.
   Retrieving the capabilities of a PCP-controlled device would allow to
   avoid error, provide a hint why some applications fails, help select
   the OpCode to issue, etc.

   This option can be elected to be defined as a new OpCode.

   This option has been defined first in [I-D.boucadair-pcp-extensions].

2.  CAPABILITY

   The CAPABILITY option (Code: TBA, Figure 1) is used by a PCP Server
   to indicate to a requesting PCP Client the capabilities it supports
   with regards to port forwarding operations.

   Several Capability options MAY be conveyed in the same PCP response
   message if several functions are co-located in the same PCP-
   controlled device (e.g., NAT44 and NAT64, NAT44 and ports set
   assignment capability, etc.).

   This option, when received from a PCP Server, is used by a PCP Client
   to constraint the content of its requests and therefore avoid errors.

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       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | CAPABILITY    |  Reserved     |            0x01               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |F T P A S C I O|              00...00                          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

         This Option:

         Option Name: PCP Capabilities Option (CAPABILITY)
         Number: TBA (IANA)
         Purpose: Retrieve the capabilities of a PCP-controlled device
         Valid for Opcodes: ANNOUNCE, MAP, PEER
         Length: 0x01
         May appear in: both request and response
         Maximum occurrences: None

                        Figure 1: Capability option

   Below is provided a description of the F, T, P, A, S, C, I and O
   bits:

   Name Description
   ---- ----------------------------------------------------------------
     F  This bit indicates the address family of the source address
        issued by internal hosts
     T  This bit indicates the address family of the source address of
        the packets forwarded in the external side of the PCP-controlled
        device
     P  This bit indicates whether the source port number is translated
        or not.
     A  This bit indicates whether the source IP address is translated
        or not.
     S  This bit indicates whether the controlled device supports the
        ability to assign a set or ports
     C  This bit indicates whether the PCP-controlled devices inspects
        the received packets and if it can block them
     I  This bit indicates whether incoming packets are rejected unless
        an explicit rule is enforced in the PCP-controlled device
     O  This bit indicates whether outbound packets are inspected or not
        before being granted to leave the internal realm.

   The value of the F, T, P, A, S, C, I and O bits are as follows:

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        Position Name               Meaning
        -------- ------------------ ------------------------------
            1    From (F)           0=from IPv4, 1=from IPv6
            2    To (T)             0=to IPv4, 1=to IPv6
            3    Port-Xlate (P)     1=translated, 0=not translated
            4    Addr-Xlate (A)     1=translated, 0=not translated
            5    Port-Set (S)       1=enabled, 0=not supported
            6    Packet-Control (C) 1=enabled, 0=not supported
            7    Direction-Out (I)  1=enabled, 0=disabled
            8    Direction-In (O)   1=enabled, 0=disabled

   A stateless NAT64 [RFC6145] would have the following values:

     From=0 (IPv4)
     To=1 (IPv6)
     Port-Xlate=0 (No)
     Addr-Xlate=1 (Yes)
     Port-Set=0  (No)
     Packet-control=0 (No)
     Direction-out (0) (No)
     Direction-In=0 (No)

   A stateful NAT64 [RFC6146] would have the following values:

     From=0 (IPv4)
     To=1 (IPv6)
     Port-Xlate=1 (Yes)
     Addr-Xlate=1 (Yes)
     Port-Set=0  (No)
     Packet-control=0 (No)
     Direction-out (0) (No)
     Direction-In=0 (No)

   A NAT44 would be characterized as follows:

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     From=0 (IPv4)
     To=0 (IPv4)
     Port-Xlate=1 (Yes)
     Addr-Xlate=1 (Yes)
     Port-Set=0  (No)
     Packet-control=0 (No)
     Direction-out (0) (No)
     Direction-In=0 (No)

   An A+P Port Range Router [RFC6346] would be characterized as follows:

     From=0 (IPv4)
     To=0 (IPv4)
     Port-Xlate=0 (No)
     Addr-Xlate=0 (No)
     Port-Set=1  (Yes)
     Packet-control=0 (No)
     Direction-out (0) (No)
     Direction-In=0 (No)

3.  Security Considerations

   Security considerations discussed in [I-D.ietf-pcp-base] must be
   considered.

4.  IANA Considerations

   The following PCP Option Code are to be allocated:
      CAPABILITY

5.  References

5.1.  Normative References

   [I-D.ietf-pcp-base]
              Wing, D., Cheshire, S., Boucadair, M., Penno, R., and P.
              Selkirk, "Port Control Protocol (PCP)",
              draft-ietf-pcp-base-26 (work in progress), June 2012.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC6145]  Li, X., Bao, C., and F. Baker, "IP/ICMP Translation

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              Algorithm", RFC 6145, April 2011.

   [RFC6146]  Bagnulo, M., Matthews, P., and I. van Beijnum, "Stateful
              NAT64: Network Address and Protocol Translation from IPv6
              Clients to IPv4 Servers", RFC 6146, April 2011.

5.2.  Informative References

   [I-D.boucadair-pcp-extensions]
              Boucadair, M., Penno, R., and D. Wing, "Some Extensions to
              Port Control Protocol (PCP)",
              draft-boucadair-pcp-extensions-03 (work in progress),
              April 2012.

   [RFC6346]  Bush, R., "The Address plus Port (A+P) Approach to the
              IPv4 Address Shortage", RFC 6346, August 2011.

Authors' Addresses

   Mohamed Boucadair
   France Telecom
   Rennes,   35000
   France

   Email: mohamed.boucadair@orange.com

   Reinaldo Penno
   Cisco
   USA

   Email: repenno@cisco.com

   Dan Wing
   Cisco Systems, Inc.
   170 West Tasman Drive
   San Jose, California  95134
   USA

   Email: dwing@cisco.com

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