3GPP IMS Option for IKEv2
draft-gundavelli-ipsecme-3gpp-ims-options-00
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| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 7651.
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|
|---|---|---|---|
| Authors | Aeneas Noble, Sri Gundavelli , Jouni Korhonen , Florin Baboescu | ||
| Last updated | 2013-02-18 | ||
| RFC stream | (None) | ||
| Formats | |||
| IETF conflict review | conflict-review-gundavelli-ipsecme-3gpp-ims-options, conflict-review-gundavelli-ipsecme-3gpp-ims-options, conflict-review-gundavelli-ipsecme-3gpp-ims-options, conflict-review-gundavelli-ipsecme-3gpp-ims-options, conflict-review-gundavelli-ipsecme-3gpp-ims-options, conflict-review-gundavelli-ipsecme-3gpp-ims-options | ||
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| IESG | IESG state | Became RFC 7651 (Informational) | |
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draft-gundavelli-ipsecme-3gpp-ims-options-00
IPSECME WG A. Noble
Internet-Draft S. Gundavelli
Intended status: Standards Track Cisco
Expires: August 22, 2013 J. Korhonen
Nokia Siemens Networks
F. Baboescu
Broadcom Corporation
February 18, 2013
3GPP IMS Option for IKEv2
draft-gundavelli-ipsecme-3gpp-ims-options-00.txt
Abstract
This document defines two new configuration attributes for Internet
Key Exchange Protocol version 2 (IKEv2). These attributes can be
used for carrying the IPv4 and IPv6 address of the Proxy-Call Control
and Service function (P-CSCF). This is one of the few methods that
an IPsec client can obtain the IP address of the P-CSCF function
located in the home network.
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 August 22, 2013.
Copyright Notice
Copyright (c) 2013 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
publication of this document. Please review these documents
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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. Conventions and Terminology . . . . . . . . . . . . . . . . . . 3
2.1. Conventions . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 4
3. P-CSCF_IP4_ADDRESS Configuration Attribute . . . . . . . . . . 4
4. P-CSCF_IP6_ADDRESS Configuration Attribute . . . . . . . . . . 5
5. Example Scenario . . . . . . . . . . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
7. Security Considerations . . . . . . . . . . . . . . . . . . . . 7
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7
9.1. Normative References . . . . . . . . . . . . . . . . . . . 7
9.2. Informative References . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8
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1. Introduction
The 3GPP S2b reference point [TS23402], specified by the 3GPP system
architecture defines a mechanism for allowing a mobile node attached
in an untrusted non-3GPP IP Access Network to securely connect to the
3GPP home network and access IP services. In this scenario, the
mobile node establishes an IPsec tunnel to the security gateway
called ePDG and which in turn establishes a PMIPv6/GTP tunnel to the
PDN gateway where the mobile node's session is anchored. The below
figure shows the interworking option for Untrusted Non-3GPP access.
+------------+
| ePDG |
| +--------+ |
+------+ _----_ | | IPsec | | _----_ +-----+
| MN | _( )_ | | Module | | _( )_ | LMA |
| |<====( Internet )=====| +--------+ |===( Operator )===|(PGW)|
+------+ (_ _) | : | (_Network_) +-----+
'----' | +--------+ | '----'
IPsec Tunnel | | PMIPv6 | | PMIPv6/GTP Tunnel
| | MAG | |
| +--------+ |
+------------+
|<------------ IKEv2/IPsec ------> | <-------------PMIPv6/GTP-->|
Figure 1: Exchange of IPv4 Traffic Offload Selectors
A mobile node in this scenario may potentially need to access the IMS
services in the home network. Currently, there are no attributes in
IKEv2 that can be used for carrying these information elements. In
the absence of these Attributes the mobile node needs to be
statically configured with this information and this is proving to be
an operational challenge.
This specification therefore defines two new IKEv2 attributes
[RFC5996] that allows an IPsec gateway to provide the IPv4 and/or
IPv6 address of the P-CSCF function. These attributes can be
exchanged by IKEv2 peers as part of the configuration payload
exchange.
2. Conventions and Terminology
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2.1. Conventions
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].
2.2. Terminology
All the IKEv2 related terms used in this document are to be
interpreted as defined in [RFC5996] and [RFC5739]. All the mobility
related terms are to interpreted as defined in [RFC5213] and
[RFC5844]. Additionally, this document uses the following terms:
Proxy-Call Session Control Function (P-CSCF)
The P-CSCF is the entry point to the 3GPP IMS (IP Multimedia
Subsystem) domain and serves as the outbound proxy server for the
mobile node. The mobile node attaches to the P-CSCF prior to
performing IMS registrations and initiating SIP sessions.
3. P-CSCF_IP4_ADDRESS Configuration Attribute
The P-CSCF_IP4_ADDRESS configuration attribute is formatted as
follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|R| Attribute Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: IPv4 Address of P-CSCF
Reserved (1 bit)
Refer to IKEv2 specification
Attribute Type (15 bits)
<IANA-1>
Length (2 octets)
Length of the value field in octets. In this case, its 4.
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IPv4 Address (4 octets)
An IPv4 address of the P-CSCF function.
Multiple instances of this Attribute with different values can be
present in the configuration payload and there is no implied
preferrential order.
4. P-CSCF_IP6_ADDRESS Configuration Attribute
The P-CSCF_IP4_ADDRESS configuration attribute is formatted as
follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|R| Attribute Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| |
| IPv6 Address |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: IPv6 Address of P-CSCF
Reserved (1 bit)
Refer to IKEv2 specification
Attribute Type (15 bits)
<IANA-1>
Length (2 octets)
Length of the value field in octets. In this case, its 16.
IPv6 Address (16 octets)
An IPv4 address of the P-CSCF function.
Multiple instances of this Attribute with different values can be
present in the configuration payload and there is no implied
preferrential order.
5. Example Scenario
The mobile node MAY request the IP address of an P-CSCF function as
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shown below.
Client Gateway
-------- ---------
HDR(IKE_SA_INIT), SAi1, KEi, Ni -->
<-- HDR(IKE_SA_INIT), SAr1, KEr, Nr, [CERTREQ]
HDR(IKE_AUTH),
SK { IDi, CERT, [CERTREQ], AUTH, [IDr],
CP(CFG_REQUEST) =
{ INTERNAL_IP4_ADDRESS(),
INTERNAL_IP4_DNS(),
P-CSCF_IP4_ADDRESS,
P-CSCF_IP6_ADDRESS }, SAi2,
TSi = (0, 0-65535, 0.0.0.0-255.255.255.255),
TSr = (0, 0-65535, 0.0.0.0-255.255.255.255) } -->
<-- HDR(IKE_AUTH),
SK { IDr, CERT, AUTH,
CP(CFG_REPLY) =
{ INTERNAL_IP4_ADDRESS(192.0.2.234),
P-CSCF_IP4_ADDRESS,
P-CSCF_IP6_ADDRESS,
INTERNAL_IP4_DNS(198.51.100.33) },
SAr2,
TSi = (0, 0-65535, 192.0.2.234-192.0.2.234),
TSr = (0, 0-65535, 0.0.0.0-255.255.255.255) }
Figure 4: P-CSCF Attribute Exchange
6. IANA Considerations
This document requires the following two IANA actions.
o Action-1: This specification defines a new IKEv2 attribute for
carrying the IPv4 address of P-CSCF function. This attribute is
defined in Section 3. The Type value for this Attribute needs to
be assigned from the IKEv2 Configuration Payload Attribute Types
namespace defined in [RFC5996].
o Action-2: This specification defines a new IKEv2 attribute for
carrying the IPv6 address of P-CSCF function. This attribute is
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defined in Section 4. The Type value for this Attribute needs to
be assigned from the IKEv2 Configuration Payload Attribute Types
namespace defined in [RFC5996].
7. Security Considerations
This document is an extension to IKEv2 [RFC5996] and therefore it
inherits all the security properties of IKEv2.
The two new IKEv2 attributes defined in this specification are for
carrying the IPv4 and IPv6 address of the P-CSCF function. These
attributes can be exchanged by IKE peers as part of the configuration
payload and the currently defined IKEv2 security framework provides
the needed integrity and privacy protection for these attributes.
Therefore this specification does not introduce any new security
vulnarabilities.
8. Acknowledgements
The Authors would like to thank Vojislav Vuecetic, Heather Sze,
Sebastian Speicher, Maulik Vaidya for all the discussions related to
this topic.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC5996] Kaufman, C., Hoffman, P., Nir, Y., and P. Eronen,
"Internet Key Exchange Protocol Version 2 (IKEv2)",
RFC 5996, September 2010.
9.2. Informative References
[RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K.,
and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008.
[RFC5739] Eronen, P., Laganier, J., and C. Madson, "IPv6
Configuration in Internet Key Exchange Protocol Version 2
(IKEv2)", RFC 5739, February 2010.
[RFC5844] Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy
Mobile IPv6", RFC 5844, May 2010.
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[TS23402] 3GPP, "Architecture enhancements for non-3GPP accesses",
2012.
Authors' Addresses
Aeneas Noble
Cisco
30 International Pl
TEWKSBURY, MASSACHUSETTS 95134
USA
Email: noblea@cisco.com
Sri Gundavelli
Cisco
170 West Tasman Drive
San Jose, CA 95134
USA
Email: sgundave@cisco.com
Jouni Korhonen
Nokia Siemens Networks
Linnoitustie 6
Espoo FIN-02600
Finland
Email: jouni.nospam@gmail.com
Florin Baboescu
Broadcom Corporation
100 Mathilda Place
Sunnyvale, CA 94086
USA
Email: baboescu@broadcom.com>
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