PCP Working Group M. Boucadair
Internet-Draft France Telecom
Intended status: Standards Track R. Penno
Expires: February 01, 2014 D. Wing
Cisco
July 31, 2013
PCP Description Option
draft-ietf-pcp-description-option-02
Abstract
This document extends Port Control Protocol (PCP) with the ability to
associate a description with a PCP-instantiated mapping. It does so
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.
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This Internet-Draft will expire on February 01, 2014.
Copyright Notice
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document authors. All rights reserved.
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Provisions Relating to IETF Documents
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Format . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Security Considerations . . . . . . . . . . . . . . . . . . . 4
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
6.1. Normative References . . . . . . . . . . . . . . . . . . 5
6.2. Informative References . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
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 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.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DESCRIPTION | Reserved | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Description |
: :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This Option:
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Option Name: Description Option (DESCRIPTION)
Number: <to be assigned in the optional-to-process range>
Purpose: Used to associate a text description with a mapping
Valid for Opcodes: MAP, PEER
Length: Variable
May appear in: request. May appear in response only if it
appeared in the associated request.
Maximum occurrences: 1
Figure 1: Description Option
The Description field MUST carry UTF-8 encoded [RFC3629] description
text. The description text SHOULD NOT be null terminated.
This option can be used by a user (or an application) to indicate a
description associated with a given mapping such as "FTP server", "My
remote access to my CP router", "Camera", "Network attached storage
serve", etc.
3. Behavior
The DESCRIPTION option is optional to be supported by PCP servers and
PCP clients.
This option (Code TBA, Figure 1) MAY be included in a PCP MAP/PEER
request to associate a description with the requested mapping.
The PCP server MAY be configurable to accept the DESCRIPTION option.
If the PCP server does not support the DESCRIPTION option or it is
configured to ignore it, received DESCRIPTION options MUST be ignored
by the PCP server and a DESCRIPTION option MUST NOT be included in
the response. The PCP server MUST store the content of the
DESCRIPTION option only if it supports the DESCRIPTION option and if
it is configured to accept handling DESCRIPTION options it receives.
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 Option. If the DESCRIPTION option is
not included in the request, the PCP server MUST NOT include the
DESCRIPTION option in the associated response.
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The maximum length SHOULD be configurable in the PCP server. 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 PCP server and returned to the PCP
client in the response.
If the PCP server receives a DESCRIPTION option having a length which
does not exceed the maximum value configured, the PCP server MUST
record the complete sequence of the description text and MUST send
back to the PCP client the same DESCRIPTION option as the one
included in the request. If the description text carried in the
DESCRIPTION option is null terminated, the exact description text,
including Null characters, MUST be returned by the PCP server.
Invalid DESCRIPTION options (e.g., the content is not a legal UTF-8
string) MUST be ignored by the PCP server.
To update the description text of a mapping maintained by a PCP
server, the PCP client generates a PCP MAP/PEER renewal request which
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 empty DESCRIPTION option (i.e., Length set to 0)
to erase the description text associated with a mapping. Upon
receipt of a PCP renewal request which includes an empty DESCRIPTION
option, the PCP server MUST clear the description text associated
with a mapping it maintains. When sending a successful PCP response,
the PCP server MUST return back the empty DESCRIPTION option in the
response to confirm the deletion of the description text is
successfully handled.
4. Security Considerations
PCP-related security considerations are discussed in [RFC6887]. In
addition, administrators of PCP servers SHOULD configure a maximum
description length which 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 SHOULD NOT be used to
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leak privacy-related information (for example, see Section 3.2 of
[RFC6462]).
5. IANA Considerations
The following PCP Option Codes are to be allocated in the optional-
to-process range (the registry is maintained in http://www.iana.org/
assignments/pcp-parameters/pcp-parameters.xml#option-rules):
DESCRIPTION
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., Cheshire, S., Boucadair, M., Penno, R., and P.
Selkirk, "Port Control Protocol (PCP)", RFC 6887, April
2013.
6.2. Informative References
[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: mohamed.boucadair@orange.com
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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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