wdiff rfc7220.original rfc7220.txt

PCP Working Group
Internet Engineering Task Force (IETF) M. Boucadair
Internet-Draft
Request for Comments: 7220 France Telecom
Intended status:
Category: Standards Track R. Penno
Expires: August 25, 2014
ISSN: 2070-1721 D. Wing
Cisco
February 21,
April 2014

PCP

Description Option
draft-ietf-pcp-description-option-05 for the Port Control Protocol (PCP)

Abstract

This document extends the Port Control Protocol (PCP) with the
ability to associate a description with a PCP-instantiated mapping.
It does so this by defining a new DESCRIPTION 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.

Internet-Drafts are working documents an Internet Standards Track document.

This document is a product of the Internet Engineering Task Force
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This Internet-Draft will expire on August 25, 2014.
http://www.rfc-editor.org/info/rfc7220.

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Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Format . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3
3. Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Security Considerations . . . . . . . . . . . . . . . . . . . 5
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
6.1. Normative References . . . . . . . . . . . . . . . . . . 5
6.2. Informative References . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6

1. Introduction

This document extends the base PCP [RFC6887] with the ability to
associate a human-readable description with a PCP-instantiated
mapping. It does so this by defining a new DESCRIPTION option.

This PCP option can be used in both simple scenarios with a PCP client and
PCP server, as well as in more complex scenarios where an
interworking function is used to proxy between a UPnP IGD Control
Point and a PCP server [RFC6970].

Querying the PCP server to get the description text of an existing
mapping is out of scope.

2. Format

The format of the DESCRIPTION option is shown in Figure 1.

This Option:

Option Name: DESCRIPTION
Number: <TBA> 128
Purpose: Used to associate a text description with a mapping
Valid for Opcodes: MAP, PEER
Length: Variable, maximum 1016 octets.
May appear in: request. May appear in response only if it
appeared in the associated request.
Maximum occurrences: 1

Figure 1: Description DESCRIPTION Option

The 'Reserved' field is initialized as specified in section Section 7.3 of
[RFC6887].

The Description field MUST carry UTF-8 encoded [RFC3629] description
text. The description text MUST NOT be null terminated. The length
of the description text is indicated by the Length field. In
particular, the description text is not null terminated terminated, and when a
client or server receives a DESCRIPTION option, it MUST NOT rely on
the presence of a NUL character in the wire format data to identify
the end of the text.

This option can be used by a user (or an application) to indicate a
description associated with a given mapping mapping, such as "FTP server",
"My remote access to my CP router", "Camera", "Network attached
storage serve", etc.

How the content of the DESCRIPTION option is used is deployment-
specific. For example, the description text can be used by the
entity managing the PCP server for many purposes purposes, such as the
following:

o The description text can be used as a hint when cleaning a mapping
table by an administrator.

o In some deployments making use of a portal to instruct PCP
mappings (e.g., Section 5.2 of
[I-D.boucadair-pcp-deployment-cases]), [PCP-DEPLOY]), the description text
can be used to store a subscriber identifier . identifier.

3. Behavior

The

Support for the DESCRIPTION option is optional to be supported by PCP servers and PCP clients. clients is
optional. This option (Code TBA, 128; see Figure 1) MAY be included in a
PCP MAP/PEER request to associate a description with the requested
mapping.

A PCP server MAY ignore the DESCRIPTION option sent to it by a PCP
client (e.g., if it does not support the option, option or if it is
configured to ignore it). To signal that it has not accepted the
option, a PCP server simply does not include the DESCRIPTION option
in the response. If the PCP client does not receive a DESCRIPTION
option in a response to a request enclosing a DESCRIPTION option,
this means the PCP server does not support that the option or it is
configured to ignore it.

If the DESCRIPTION option is not included in the PCP client request,
the PCP server MUST NOT include the DESCRIPTION option in the
associated response.

Because of the UDP payload limit of 1100 octets [RFC6887], the
configured maximum length MUST NOT exceed 1016 octets. The suggested
maximum length is 128 octets. If a PCP client includes a DESCRIPTION
option with a length exceeding the maximum length supported by the
PCP server, only the portion of the Description field fitting that
maximum length is stored by the

A PCP server and returned SHOULD be able to the PCP
client in the response.

If store at least 128 bytes for a
description. When the PCP server receives a DESCRIPTION option having a length which
does not exceed option, it
first stores the maximum value configured, the PCP server MUST
record the complete sequence of the description text and received Description field, truncating
it if it cannot store the entire value. The server MUST then send
the stored value back to the PCP client in the same DESCRIPTION option as the one
included in
the request. response.

If the PCP client request contains invalid DESCRIPTION options (e.g.,
the content is not a legal UTF-8 string), the PCP server MUST ignore
the request (i.e., MUST NOT return a DESCRIPTION option in the
response).

To update the description text of a mapping maintained by a PCP
server, the PCP client generates a PCP MAP/PEER renewal request which that
includes a DESCRIPTION option carrying the new description text.
Upon receipt of the PCP request, the PCP server proceeds to the same
operations to validate a MAP/PEER request refreshing an existing
mapping. If validation checks are successfully passed, the PCP
server replaces the old description text with the new one included in
the DESCRIPTION option, and the PCP server returns the updated
description text in the response, truncated (if necessary) as
described above.

The PCP client uses an empty DESCRIPTION option (i.e., Length set to
0) to erase the description text associated with a mapping. To
indicate that the PCP server has successfully cleared the description
text associated with a mapping, the PCP server returns back the empty
DESCRIPTION option in the response.

4. Security Considerations

PCP-related security considerations are discussed in [RFC6887]. In
addition, administrators of PCP servers SHOULD configure a maximum
description length which that does not lead to exhausting storage resources
in the PCP server.

If the PCP client and the PCP server are not under the same
administrative entity, the DESCRIPTION option has the potential to
leak privacy-related information. PCP clients should not use the
DESCRIPTION option for such leakage. For example, the option should
not be used to include user identifiers, locations, or names. Refer
to Section 3.2 of [RFC6462] for a discussion on information leakage.

5. IANA Considerations

The following PCP Option Codes are to be

IANA has allocated the following value in the "PCP Options" registry
(http://www.iana.org/assignments/pcp-parameters) from the optional-
to-process range (the registry is maintained in http://www.iana.org/
assignments/pcp-parameters): (see Section 19.4 of [RFC6887]):

DESCRIPTION set to TBA 128 (see Section 2)

6. References

6.1. Normative References

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

[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, November 2003.
[RFC6887] Wing, D., Ed., Cheshire, S., Boucadair, M., Penno, R., and
P. Selkirk, "Port Control Protocol (PCP)", RFC 6887, April
2013.

6.2. Informative References

[I-D.boucadair-pcp-deployment-cases]

[PCP-DEPLOY]
Boucadair, M., "PCP "Port Control Protocol (PCP) Deployment
Models", draft-boucadair-
pcp-deployment-cases-01 (work Work in progress), December 2013. Progress, April 2014.

[RFC6462] Cooper, A., "Report from the Internet Privacy Workshop",
RFC 6462, January 2012.

[RFC6970] Boucadair, M., Penno, R., and D. Wing, "Universal Plug and
Play (UPnP) Internet Gateway Device - Port Control
Protocol Interworking Function (IGD-PCP IWF)", RFC 6970,
July 2013.

Authors' Addresses

Mohamed Boucadair
France Telecom
Rennes 35000
France

Email:

EMail: mohamed.boucadair@orange.com

Reinaldo Penno
Cisco
USA

Email:

EMail: repenno@cisco.com

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

Email:

EMail: dwing@cisco.com