Internet DRAFT - draft-korhonen-netext-rfc5149bis
draft-korhonen-netext-rfc5149bis
Network-Based Mobility Extensions J. Korhonen
(Netext) Nokia Siemens Networks
Internet-Draft U. Nilsson
Obsoletes: 5149 (if approved) TeliaSonera
Updates: 5213 (if approved) V. Devarapalli
Intended status: Standards Track March 12, 2012
Expires: September 13, 2012
Service Selection for Mobile IPv6
draft-korhonen-netext-rfc5149bis-02.txt
Abstract
In some Mobile IPv6 deployments, identifying the mobile node or the
mobility service subscriber is not enough to distinguish between
multiple services possibly provisioned to the said mobile node and
its mobility service subscription. A capability to specify different
services in addition to the mobile node identity can be leveraged to
provide flexibility for mobility service providers on provisioning
multiple services to one mobility service subscription. This
document describes a Service Selection Mobility Option for both
conventional Mobile IPv6 and Proxy Mobile IPv6 that is intended to
assist home agents and local mobility agents to make a specific
service selection for the mobility service subscription during the
binding registration procedure. This specification updates RFC5213
and obsoletes RFC5149.
Requirements
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
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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."
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This Internet-Draft will expire on September 13, 2012.
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
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
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.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Service Selection Mobility Option . . . . . . . . . . . . . . 5
3. Processing Considerations . . . . . . . . . . . . . . . . . . 6
3.1. Binding Cache Entry Lookup Considerations . . . . . . . . 6
3.2. Mobile Node Considerations . . . . . . . . . . . . . . . . 6
3.3. Home Agent and Local Mobility Agent Considerations . . . . 7
3.4. Correspondent Node Considerations . . . . . . . . . . . . 8
4. Security Considerations . . . . . . . . . . . . . . . . . . . 9
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6.1. Normative references . . . . . . . . . . . . . . . . . . . 9
6.2. Informative references . . . . . . . . . . . . . . . . . . 10
Appendix A. Changes to RFC5149 . . . . . . . . . . . . . . . . . 10
A.1. Note #1 . . . . . . . . . . . . . . . . . . . . . . . . . 11
A.2. Note #2 . . . . . . . . . . . . . . . . . . . . . . . . . 11
A.3. Note #3 . . . . . . . . . . . . . . . . . . . . . . . . . 11
A.4. Note #4 . . . . . . . . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11
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1. Introduction
Mobile IPv6 [RFC6275] can identify mobile nodes in various ways,
including home addresses, Network Access Identifiers (NAIs)
[RFC4282][RFC4283], and credentials suitable for the Internet Key
Exchange Protocol version 2 (IKEv2) [RFC4877]. Proxy Mobile IPv6
[RFC5213] uses Home Network Prefix (HNP) and/or Mobile Node
Identifier [RFC4283]. In some Mobile IPv6 deployments, identifying
the mobile node or the mobility service subscriber via a Proxy Mobile
IPv6 client [RFC5213] (hereafter, the mobile node and the Proxy
Mobile IPv6 client are used interchangeably) is not enough to
distinguish between multiple services possibly provisioned to the
said mobile node and its mobility service subscription.
The capability to specify different services in addition to the
mobile node identity can be leveraged to provide flexibility for
mobility service providers to provide multiple services within the
same mobility service subscription. For example:
o Provide an enterprise data access for which the mobility service
provider hosts connectivity and mobility services on behalf of the
enterprise.
o Provide access to service domains that are otherwise not
accessible from public networks because of some mobility service
provider's business reasons.
o Provide simultaneous access to different service domains that are
separated based on policies of the mobility service provider.
o Enable easier policy and quality of service assignment for
mobility service providers based on the subscribed services.
o In the absence of a specifically indicated service, the home agent
MUST act as if the default service, plain Internet access, had
been requested. There is no absolute requirement that this
default service be allowed to all subscribers, but it is highly
RECOMMENDED in order to avoid having normal subscribers employ
operator-specific configuration values in order to get basic
service.
This document describes a Service Selection Mobility Option for
(Proxy) Mobile IPv6 that is intended to assist home agents or local
mobility agents to make specific service selections for the mobility
service subscription during the binding registration procedure. The
service selection MAY affect home agent or local mobility agent
routing decisions, Home Address or Home Network Prefix assignment
policies, firewall settings, and security policies. The Service
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Selection option SHOULD be used in every Binding Update that makes a
new registration to the home agent.
Some of the potential use-cases were listed earlier in this section.
The general aim is better manageability of services and service
provisioning from the point of view of both operators and service
providers. However, it should be understood that there are potential
deployment possibilities where selecting a certain service may
restrict simultaneous access to other services from a user's point of
view. For example, services may be located in different
administrative domains or external customer networks that practice
excessive filtering of inbound and outbound traffic.
There are existing deployments using the Service Selection option.
3GPP PMIPv6-based Evolved Packet Core (EPC) [RFC6459] deployments use
the Service Selection option to carry the Access Point Name (APN)
[TS.23003]. Recently, service provider Wi-Fi services over
residential architectures [I-D.gundavelli-v6ops-community-wifi-svcs]
that intend to integrate into e.g., 3GPP EPC using PMIPv6, need
Service Selection option again to carry the APN information for
identifying a particular routing domain.
2. Service Selection Mobility Option
At most one Service Selection Mobility option SHOULD be included in
any (Proxy) Binding Update message. If and only if the (Proxy)
Binding Update message included the Service Selection Option, then
the corresponding (Proxy) Binding Acknowledgement message SHOULD also
contain the Service Selection option with the service name in the
Identifier (see Note #1 in Appendix A.1).
If the (Proxy) Binding Update message includes any authorization-
related options (such as the Binding Authorization Data option
[RFC6275]) or authentication related options (such as the Mobility
Message Authentication option [RFC4285]), then the Service Selection
option MUST appear before any mobility message authorization- or
authentication-related options.
The Service Selection option SHOULD NOT be sent to a correspondent
node. The mobile node cannot assume that the correspondent node has
any knowledge about a specific service selection made between the
mobile node and the home agent.
The Service Selection option has no alignment requirement as such.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 20 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier... ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Service Selection Mobility Option
o Type: 8-bit identifier set to 20 of the type of the skipable
mobility option.
o Length: 8-bit unsigned integer, representing the length of the
Service Selection Mobility Option in octets, excluding the Option
Type and Option Length fields. A value of zero (0) is not
allowed.
o Identifier: A variable-length encoded service identifier string
used to identify the requested service. The identifier string
length is between 1 and 255 octets. This specification allows
international identifier strings that are based on the use of
Unicode characters, encoded as UTF-8 [RFC3269], and formatted
using Normalization Form KC (NFKC) as specified in [NFKC] (see
Note #2 in Appendix A.2).
'ims', 'voip', and 'voip.companyxyz.example.com' are valid
examples of Service Selection option Identifiers. At minimum, the
Identifier MUST be unique among the home agents to which the
mobile node is authorized to register.
3. Processing Considerations
3.1. Binding Cache Entry Lookup Considerations
Section 5.4.1 of [RFC5213] describes various Binding Cache Entry
(BCE) lookup variations in the local mobility agent. Some existing
Proxy Mobile IPv6 deployments have added the Service Selection option
as one of the used BCE lookup keys (see Note #3 in Appendix A.3).
This implies that the Service Selection option SHOULD be included in
all Proxy Binding Update messages, especially when the Home Network
Prefix is not readily available.
3.2. Mobile Node Considerations
A mobile node or a Proxy Mobile IPv6 client MAY include, at most, one
Service Selection Mobility Option into a (Proxy) Binding Update
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message. The option is used to identify the service to be associated
with the binding registration and SHOULD only be included into the
initial Binding Update message sent to a home agent. If the mobile
node wishes to change the selected service, it is RECOMMENDED that
the mobile node de-register the existing binding with the home agent
before proceeding with a binding registration for a different
service. The provisioning of the service identifiers to the mobile
node or to the Proxy Mobile IPv6 client is out of the scope of this
specification.
The placement of the Service Selection option is as follows: when
present, this option MUST appear after the Mobile Node-Network Access
Identifier (MN-NAI) option, if the MN-NAI option is present, and
before any authorization- and authentication-related options. The
Service Selection option can be used with any mobile node
identification method such as a home address, an MN-NAI, and
credentials suitable for IKEv2.
If the mobile node receives a (Proxy) Binding Acknowledgement with a
Status Code set to SERVICE_AUTHORIZATION_FAILED and the mobile node
has an existing binding with the Home Address or the Home Network
Prefix used in the failed (Proxy) Binding Update message, the mobile
node MUST delete the existing binding. If there is no existing
binding, the mobile node proceeds as with any failed initial binding
registration.
If the mobile node receives a (Proxy) Binding Acknowledgement with a
Status Code set to MISSING_OR_UNKNOWN_SERVICE the mobile node
proceeds as with any failed initial binding registration. The mobile
node SHOULD log the event as it is usually an indication of a
configuration error.
3.3. Home Agent and Local Mobility Agent Considerations
Upon receiving a (Proxy) Binding Update message with a Service
Selection option, the home agent or the local mobility agent
authenticates and authorizes the mobile node. If the home agent or
the local mobility anchor supports the Service Selection and the
Service Selection is required by the local policy, the home agent or
the local mobility anchor MUST also verify that the mobile node is
authorized for the service it included in the Service Selection
option. The services the mobile node is authorized for SHOULD be
part of the general mobile node subscription profile. If the mobile
node is not authorized for the service, the home agent or the local
mobility agent MUST deny the registration and send a (Proxy) Binding
Acknowledgement with a Status Code set to
SERVICE_AUTHORIZATION_FAILED (151). If the (Proxy) Binding Update
does not contain the Service Selection option or the indicated
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service is unknown, the home agent or the local mobility agent SHOULD
deny the registration and send a (Proxy) Binding Acknowledgement with
a Status Code set to MISSING_OR_UNKNOWN_SERVICE (TBD) (see Note #4 in
Appendix A.4).
If binding registration was successful in the home agent or the local
mobility agent, then the (Proxy) Binding Acknowledgement SHOULD
contain the Service Selection option with the service name in the
Identifier.
The Service Selection option is used to assist the authorization and
identifies a specific service that is to be authorized. The Service
Selection option MAY also affect the Home Address or the Home Network
Prefix allocation when, for example, used with the MN-NAI option.
For example, for the same NAI there MAY be different Home Addresses
or Home Network Prefixes depending on the identified service.
Furthermore, the Service Selection option MAY also affect the routing
of the outbound IP packets in the home agent or the local mobility
agent depending on the selected service. The home agent MAY also
apply different policy or quality of service treatment to traffic
flows based on the selected service.
If the newly arrived (Proxy) Binding Update message with a Service
Selection option indicates a change in the selected service, then the
home agent MUST re-authorize the mobile node. Depending on the home
agent or the local mobility agent policies, the services policies,
Home Address or Home Network Prefix allocation policies, and the
subscription policies, the home agent may or may not be able to
authorize the mobile node to the new service. For example, the
existing service and the new service could require different Home
Network Prefixes. If the authorization fails, then the home agent or
the local mobility agent MUST deny the registration, delete any
binding with the existing Home Address or Home Network Prefix, and
send a (Proxy) Binding Acknowledgement with a Status Code set to
SERVICE_AUTHORIZATION_FAILED (151).
3.4. Correspondent Node Considerations
Unless the correspondent node and the home agent share the same
knowledge about mobility services, the Service Selection option is
more or less useless information to the correspondent node. The
correspondent node SHOULD silently ignore the Service Selection
option in this case.
There are deployment cases where the home agent and a correspondent
node, for example, belong to the same administrative domain. In this
case, it is possible that the correspondent node shares the same
knowledge of the services as the home agent. Therefore, the
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correspondent node is, for example, able to provide service-based
traffic handling to mobile nodes.
4. Security Considerations
The protection for the Service Selection Mobility Option depends on
the service that is being identified and eventually selected. If the
service selection information should not be revealed on the wire,
(Proxy) Binding Updates and (Proxy) Binding Acknowledgements should
use Encapsulating Security Payload (ESP) [RFC4303] in transport mode
with a non-null encryption transform to provide message
confidentiality.
5. IANA Considerations
A Mobile IPv6 Mobility Option type has been assigned for the
following new mobility option from [RFC6275] "Mobility Options"
registry. The mobility option is defined in Section 2:
Service Selection Mobility Option is set to 20
A Mobile IPv6 registration denied by home agent Status Code has been
assigned. The Status Code was allocated from the range 128-255:
SERVICE_AUTHORIZATION_FAILED is set to 151
MISSING_OR_UNKNOWN_SERVICE is set to TBD
6. References
6.1. Normative references
[NFKC] Davis, M. and M. Durst, "Unicode Standard Annex #15;
Unicode Normalization Forms", Unicode 5.0.0, October 2006.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K.,
and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008.
[RFC6275] Perkins, C., Johnson, D., and J. Arkko, "Mobility Support
in IPv6", RFC 6275, July 2011.
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6.2. Informative references
[I-D.gundavelli-v6ops-community-wifi-svcs]
Gundavelli, S., Grayson, M., Seite, P., and Y. Lee,
"Service Provider Wi-Fi Services Over Residential
Architectures",
draft-gundavelli-v6ops-community-wifi-svcs-03 (work in
progress), March 2012.
[RFC1035] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, November 1987.
[RFC3269] Kermode, R. and L. Vicisano, "Author Guidelines for
Reliable Multicast Transport (RMT) Building Blocks and
Protocol Instantiation documents", RFC 3269, April 2002.
[RFC4282] Aboba, B., Beadles, M., Arkko, J., and P. Eronen, "The
Network Access Identifier", RFC 4282, December 2005.
[RFC4283] Patel, A., Leung, K., Khalil, M., Akhtar, H., and K.
Chowdhury, "Mobile Node Identifier Option for Mobile IPv6
(MIPv6)", RFC 4283, November 2005.
[RFC4285] Patel, A., Leung, K., Khalil, M., Akhtar, H., and K.
Chowdhury, "Authentication Protocol for Mobile IPv6",
RFC 4285, January 2006.
[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)",
RFC 4303, December 2005.
[RFC4877] Devarapalli, V. and F. Dupont, "Mobile IPv6 Operation with
IKEv2 and the Revised IPsec Architecture", RFC 4877,
April 2007.
[RFC6459] Korhonen, J., Soininen, J., Patil, B., Savolainen, T.,
Bajko, G., and K. Iisakkila, "IPv6 in 3rd Generation
Partnership Project (3GPP) Evolved Packet System (EPS)",
RFC 6459, January 2012.
[TS.23003]
3GPP, "Numbering, addressing and identification", 3GPP
TS 23.003 10.2.0, June 2011.
Appendix A. Changes to RFC5149
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A.1. Note #1
3GPP EPC PMIPv6-based interfaces echo the Service Selection option
always back in Proxy Binding Acknowledgements. This is clarified
from the RFC5149, which did not say anything about the Service
Selection option in Proxy Binding Acknowledgement messages.
A.2. Note #2
3GPP EPC decided to encode their Service Selection Identifiers using
the [RFC1035] domain name encoding [TS.23003]. Implementations has
to take this into account when they intend to interoperate with 3GPP
EPC.
A.3. Note #3
3GPP EPC use the Service Selection option as one of the BCE lookup
keys. This is additional to what RFC5213 originally defined.
A.4. Note #4
RFC5149 did not make a difference between a service authorization
failure (SERVICE_AUTHORIZATION_FAILED) and a service not being
provisioned in a home agent/local mobility agent or otherwise unknown
(MISSING_OR_UNKNOWN_SERVICE).
Authors' Addresses
Jouni Korhonen
Nokia Siemens Networks
Linnoitustie 6
FIN-02600 Espoo
Finland
Email: jouni.nospam@gmail.com
Ulf Nilsson
TeliaSonera Corporation
Marbackagatan 11
S-123 86 Farsta
SWEDEN
Email: ulf.s.nilsson@teliasonera.com
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Vijay Devarapalli
Email: dvijay@gmail.com
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