One document matched: draft-boucadair-pcp-extensions-00.txt
Network Working Group M. Boucadair
Internet-Draft France Telecom
Intended status: Standards Track R. Penno
Expires: November 21, 2011 Juniper Networks
D. Wing
Cisco
May 20, 2011
Some Extensions to Port Control Protocol (PCP)
draft-boucadair-pcp-extensions-00
Abstract
This document extends Port Control Protocol (PCP) with some useful
features.
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 of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on November 21, 2011.
Copyright Notice
Copyright (c) 2011 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
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
Boucadair, et al. Expires November 21, 2011 [Page 1]
Internet-Draft Extensions to PCP May 2011
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. DSCP_POLICY . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. CAPABILITY . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5. PERCEIVED_ADDRESS . . . . . . . . . . . . . . . . . . . . . . 8
6. SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7. REPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
8. CLIENT_IDENTIFIER . . . . . . . . . . . . . . . . . . . . . . 12
9. Security Considerations . . . . . . . . . . . . . . . . . . . 14
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14
12. Normative References . . . . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15
Boucadair, et al. Expires November 21, 2011 [Page 2]
Internet-Draft Extensions to PCP May 2011
1. Introduction
This document extends the base PCP protocol [I-D.ietf-pcp-base] with
various PCP Options.
Some of these options may be defined as new PCP OpCodes.
The main goal of this document is to kick-off discussions on the need
to define some useful PCP options which are not part of base PCP.
2. DESCRIPTION
This option (Code TBA, Figure 1) MAY be included in a PCP MAPx
request to include a description associated with a requested mapping.
This option is optional to be supported by PCP Servers and PCP
Clients. The maximum length SHOULD be a configurable option in the
PCP Server. If a PCP Client includes a Description PCP 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.
This option can be used by a user to indicate a description
associated with a given mapping such as "My mapping for my FTP
server" or "My remote access to my CP router", etc. In addition, in
the some deployment scenarios, this field can be used for
troubleshooting purposes and can be used to convey values as the ones
listed hereafter:
o "This is the mapping for my specific IPsec implementation"
o "This is the mapping for subscriber bob@example.com"
o "This is the mapping for special subscriber
adsl-line-1234@example.com"
o "This is the mapping that failed before due to XYZ"
Issues related to the usage of this field for troubleshooting or for
any further usage are out of scope of this document.
Boucadair, et al. Expires November 21, 2011 [Page 3]
Internet-Draft Extensions to PCP May 2011
This Option:
Name: Description Option (DESCRIPTION)
Number: TBA (IANA)
Purpose: Used to associate a text description with a mapping
is valid for OpCodes: MAP4, MAP6
Length: Variable (multiple of 4)
May appear in: both request and response
Maximum occurrences: 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 |
: :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Description Option
3. DSCP_POLICY
In some scenarios, the DSCP marking in the internal interface (i.e.,
customer-facing interface) and the external one (i.e., Internet-
facing interface) of the PCP-controlled device may be distinct. A
Service Provider MAY allow its customers to configure their DSCP
marking policies in an upstream device. Distinct DSCP marking
policies can be implemented in the internal and external sides of the
PCP-controlled device. A PCP Client MAY issue a PCP MAPx request
indicating its internal DS code point and the external DSCP value.
Instructed forwarding policies are applied only for packets marked
with a given DSCP value.
A Service Provider may not support DSCP re-marking feature and adopt
a transparent scheme to QoS policy enforcement, that is, not
controllable by subscribers. Generic QoS enforcement policies can be
enforced for all customers: such as leave DSCP field values
unchanged.
Boucadair, et al. Expires November 21, 2011 [Page 4]
Internet-Draft Extensions to PCP May 2011
This option (Code TBA, Figure 2) allows to:
o Re-write any DSCP value to a specific value;
o Re-write a specific DSCP value to another specific value.
This Option:
Name: PCP DSCP Marking Policy Option (DSCP_POLICY)
Number: TBA (IANA)
Purpose: Associated a DSCP re-marking policy with a mapping
is valid for OpCodes: MAP4, MAP6
Length: 0x04
May appear in: both request and response
Maximum occurrences: none
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DSCP_POLICY | Reserved | 0x04 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|DIR| Int DSCP | Ext DSCP | 00...00 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
DIR : Indicates the direction:
0 for Inbound
1 for Outbound
2 for Both
Int DSCP: Indicates the DSCP value in the customer-faced interface.
0x3F is used to indicate ANY value.
Ext DSCP: Indicates the DSCP value in the Internet-faced interface.
0x3F is used to indicate ANY value.
Figure 2: DSCP Marking option
4. CAPABILITY
The CAPABILITY option (Code: TBA, Figure 3) is used by a PCP Server
to indicate to a requesting PCP Client the capabilities it supports
Boucadair, et al. Expires November 21, 2011 [Page 5]
Internet-Draft Extensions to PCP May 2011
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.
This Option:
Name: PCP Capabilities Option (CAPABILITY)
Number: TBA (IANA)
Purpose: Retrieve the capabilities of a PCP-controlled device
is valid for OpCodes: can be returned in a error message
Length: 0x04
May appear in: both request and response
Maximum occurrences: None
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 | 0x04 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|F T P A S C I O| 00...00 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Capability option
Below is provided a description of the F, T, P, A, S, C, I and O
bits:
Boucadair, et al. Expires November 21, 2011 [Page 6]
Internet-Draft Extensions to PCP May 2011
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:
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:
Boucadair, et al. Expires November 21, 2011 [Page 7]
Internet-Draft Extensions to PCP May 2011
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:
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)
5. PERCEIVED_ADDRESS
This option (Code TBA, Figure 4) is used by a PCP Server to indicate
in a PCP Response the perceived IPv6/IPv4 address and port of PCP
messages received from a PCP Client. A PCP Client uses this
information to detect whether a NAT is present in the path to reach
its PCP Server.
A PCP Client MAY include this option to learn the IP address and port
as perceived by the PCP Server. When this option is received by the
PCP Server, it uses the source IP address and port of the received
PCP request to set the Perceived Port and Perceived IP Address.
Boucadair, et al. Expires November 21, 2011 [Page 8]
Internet-Draft Extensions to PCP May 2011
This Option:
Name: PCP Perceived IP address/port Option (PERCEIVED_ADDR )
Number: TBA (IANA)
Purpose: Detect the presence of a NAT in the path
is valid for OpCodes: MAP4, MAP6
Length: 0x08
May appear in: both request and response
Maximum occurrences: 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|PERCEIVED_ADDR | Reserved | 0x08 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Perceived Port |Address Family | 00...00 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Perceived IPv4/IPv6 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Perceived Port: The source port number of a PCP request as seen
by the PCP Server.
Address Family: The Address Family of the perceived IP address.
Perceived IPv4/IPv6 Address: If the Address Family is IPv4,
an IPv4 address followed by 96 zero bits. If the Address Family
is IPv6, an IPv6 address. This field includes the source IP
address of a PCP request as seen by the PCP Server.
Figure 4: Perceived IP address/port PCP option
An example of the use of this option is illustrated in the following
figure where there is a NAT in the path between the PCP Client and
the PCP Server.
Boucadair, et al. Expires November 21, 2011 [Page 9]
Internet-Draft Extensions to PCP May 2011
webcam-------+
|
+----------+ | +----+ +----------+
|PCP Client|====+====|NAT1|=========|PCP Server|
+----------+ +----+ +----------+
NAT2
An example of instructing mappings in the PCP Server is as follows:
o NAT1 is detected in the path between the PCP Client and the PCP
Server owing to the use of the PERCEIVED_ADDR Option;
o After learning about that NAT, the PCP Client uses UPnP IGD (or
NAT-PMP) to interact with NAT1 and open the necessary port on NAT1
(e.g., IP address= IPx, port=X);
o The PCP Client then sends PCP message to the PCP Server,
indicating IPx and X as the internal IP address and port. The PCP
Server opens pinhole towards IPx and X.
6. SCOPE
The Scope Option (Code TBA, Figure 5) is used by a PCP Client to
indicate to the PCP Server the scope of the flows that will use a
given mapping. This object is meant to be used in the context of
cascaded PCP Servers/NAT levels. Two values are defined:
Value Meaning
----- --------
0x00 Internet
0x01 Internal
When 0x00 value is used, the PCP Proxy MUST propagate the mapping
request to its upstream PCP Server. When 0x01 value is used, the
mapping is to be instantiated only in the first PCP-controlled
device; no mapping is instantiated in the upstream PCP-controlled
device.
When no Scope Option is included in a PCP message, this is equivalent
to including a Scope Option with a scope value of "Internet".
Boucadair, et al. Expires November 21, 2011 [Page 10]
Internet-Draft Extensions to PCP May 2011
This Option:
Name: PCP Scope Policy Option (SCOPE)
Number: TBA (IANA)
Purpose: Restrict the scope of PCP requests
is valid for OpCodes: MAP4, MAP6
Length: 0x04
May appear in: both request and response
Maximum occurrences: 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SCOPE | Reserved | 0x04 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Scope | 00...00 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: Scope Option
7. REPORT
The Report PCP Option (Code TBA, Figure 6) is used by a PCP Client to
report a set of useful information to the PCP Server. Several Report
Options with distinct Report Sub-Code values MAY be conveyed in the
same PCP message. Only report data associated with the PCP Server to
which this option is sent MUST be included in a Report Option.
This option can be used for troubleshooting or diagnose purposes.
Boucadair, et al. Expires November 21, 2011 [Page 11]
Internet-Draft Extensions to PCP May 2011
This Option:
Name: PCP Report Option (REPORT)
Number: TBA (IANA)
Purpose: Send a set of report data
is valid for OpCodes: MAP4, MAP6
Length: Variable
May appear in: both request and response
Maximum occurrences: Multiple
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SCOPE | Reserved | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Report Sub-Code | 00...00 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Report Data |
: :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Report Option
The following Report Sub-Code values are defined:
Position Meaning
-------- ------------------------------------------------------------
0x00 Time since last reboot/boot
0x01 Count of transmitted PCP messages to the PCP Server since
last boot
0x02 Count of retransmitted PCP messages to the PCP Server since
last boot
0x03 Count of received PCP Error messages from the PCP Server
8. CLIENT_IDENTIFIER
PCP CLIENT_ID (Code TBA, Figure 7) is a token randomly [RFC4086]
generated by the PCP Client. Only one CLIENT_ID Option MUST be
present in a PCP message. The PCP Client and PCP Server MUST store
the value included in this Option in a PCP MAPx request.
Boucadair, et al. Expires November 21, 2011 [Page 12]
Internet-Draft Extensions to PCP May 2011
o The CLIENT_ID MUST be generated by the PCP Client and not the PCP
Server;
o Upon change of the IP address of the PCP Client (or a third party
on behalf of which a mapping has been created), the CLIENT_ID is
used to update related mappings (e.g., PCP MAP delete request and
PCP MAP create request);
o The same CLIENT_ID MUST be used for all requested mappings, unless
a new CLIENT_ID is generated by the PCP Client (e.g., reboot, OS
crash, etc.);
o The CLIENT_ID is stored by the PCP Server for all mappings
(persistent storage);
This Option:
Name: PCP Client Identifier Option (CLIENT_ID)
Number: TBA (IANA)
Purpose: Associate an identifier with the mappings
is valid for OpCodes: MAP4, MAP6
Length: Variable
May appear in: both request and response
Maximum occurrences: 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CLIENT_ID | Reserved | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Client Identifier |
: :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: CLIENT_ID PCP Option
The length of the CLIENT_ID is encoded in the Length field in bytes.
The length of the CLIENT_ID MUST be at least 4 bytes and MUST NOT
exceed 16 bytes.
Boucadair, et al. Expires November 21, 2011 [Page 13]
Internet-Draft Extensions to PCP May 2011
The RECOMMENDED value is 16 bytes so as to have a robust random
CLIENT_ID. If a CLIENT_ID longer than 16 bytes or shorter than 4
bytes is received, the PCP Server MUST issue a PCP Error message with
an error cause equal to "Invalid Client-ID".
For sanity checks, a PCP Server maintains the same CLIENT_ID value
(which is used in the latest PCP request) for a given PCP Client for
all mappings associated with the same internal IP address belonging
to the same subscriber. Indeed, the PCP Server maintains an
additional identifier denoted as subscriber-Id. A subscriber-is can
be an IP address, IPv6 prefix or a subscriber identifier configured
locally.
9. Security Considerations
Security considerations discussed in [I-D.ietf-pcp-base] must be
considered. The use of CLIENT_ID option allows to soften issues
related to stale mappings.
10. IANA Considerations
The following PCP Option Code are to be allocated:
DESCRIPTION
DSCP_POLICY
CAPABILITY
PERCEIVED_ADDRESS
SCOPE
REPORT
CLIENT_IDENTIFIER
11. Acknowledgements
TBC.
12. Normative References
[I-D.ietf-pcp-base]
Boucadair, et al. Expires November 21, 2011 [Page 14]
Internet-Draft Extensions to PCP May 2011
Wing, D., Cheshire, S., Boucadair, M., and R. Penno, "Port
Control Protocol (PCP)", draft-ietf-pcp-base-11 (work in
progress), May 2011.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4086] Eastlake, D., Schiller, J., and S. Crocker, "Randomness
Requirements for Security", BCP 106, RFC 4086, June 2005.
[RFC6145] Li, X., Bao, C., and F. Baker, "IP/ICMP Translation
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.
Authors' Addresses
Mohamed Boucadair
France Telecom
Rennes, 35000
France
Email: mohamed.boucadair@orange-ftgroup.com
Reinaldo Penno
Juniper Networks
1194 N Mathilda Avenue
Sunnyvale, California 94089
USA
Email: rpenno@juniper.net
Dan Wing
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, California 95134
USA
Email: dwing@cisco.com
Boucadair, et al. Expires November 21, 2011 [Page 15]
| PAFTECH AB 2003-2026 | 2026-04-24 01:30:03 |