Wi-Fi Services Over Residential Architectures
draft-gundavelli-v6ops-community-wifi-svcs-02
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Expired".
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|---|---|---|---|
| Authors | Sri Gundavelli , Mark Grayson , Pierrick Seite , Yiu Lee | ||
| Last updated | 2012-03-07 | ||
| RFC stream | (None) | ||
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draft-gundavelli-v6ops-community-wifi-svcs-02
V6OPS WG S. Gundavelli
Internet-Draft M. Grayson
Intended status: Informational Cisco
Expires: September 8, 2012 P. Seite
France Telecom - Orange
Y. Lee
Comcast
March 7, 2012
Wi-Fi Services Over Residential Architectures
draft-gundavelli-v6ops-community-wifi-svcs-02.txt
Abstract
The tremendous growth in Wi-Fi technology adoption over the last
decade has met the ultimate possible goal of 100% adoption rate. All
most every new mobile device is now equipped with IEEE 802.11-based
wireless interface and with pre-configured policy to prefer Wi-Fi to
cellular access. Matching this evolution is every service provider's
desire to offer Wi-Fi based broadband services; a new business
opportunity even for fixed line operators. Operators are exploring
options to monetize their existing networks, most with nation-wide
footprint, to build a high-speed Wi-Fi service that can be the basis
for offering new wireless broadband services. This document
identifies the requirements for supporting these new Wi-Fi community
services and the mobility tools which have been standardized in IETF
that can be used for enabling these architectures.
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 September 8, 2012.
Copyright Notice
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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.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions and Terminology . . . . . . . . . . . . . . . . . 4
2.1. Conventions . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
3. Deployment Models . . . . . . . . . . . . . . . . . . . . . . 5
4. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1. Subscriber Authentication & Service Authorization . . . . 7
4.2. Location-based Services . . . . . . . . . . . . . . . . . 7
4.3. Local Services Access & Internet Traffic Offload . . . . . 7
4.4. Web-based Authentication Support . . . . . . . . . . . . . 8
4.5. Transparent Auto Login (TAL) . . . . . . . . . . . . . . . 8
4.6. Multiple WLAN SSID Support . . . . . . . . . . . . . . . . 8
4.7. Multiple Home Network Service (APN) Access . . . . . . . . 8
4.8. CPE Identity and Authorization . . . . . . . . . . . . . . 9
4.9. Mobility within the WLAN Access Network . . . . . . . . . 9
4.10. Mobility across WLAN and Macro Access . . . . . . . . . . 9
4.11. Differentiated Services for Users behind CPE . . . . . . . 9
4.12. Lawful Intercept (LI) . . . . . . . . . . . . . . . . . . 10
4.13. Charging & Accounting . . . . . . . . . . . . . . . . . . 11
4.14. Overlapping IPv4 Address Support . . . . . . . . . . . . . 11
4.15. Policy Provisioning . . . . . . . . . . . . . . . . . . . 11
5. Solution Approach . . . . . . . . . . . . . . . . . . . . . . 11
5.1. PMIPv6 MAG in the Residential CPE . . . . . . . . . . . . 11
5.2. PMIPv6 MAG in the Access Gateway . . . . . . . . . . . . . 11
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
7. Security Considerations . . . . . . . . . . . . . . . . . . . 12
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
9.1. Normative References . . . . . . . . . . . . . . . . . . . 12
9.2. Informative References . . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13
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1. Introduction
The tremendous growth in Wi-Fi technology adoption over the last
decade has met the ultimate possible goal of 100% adoption rate. All
most every new mobile device is now equipped with IEEE 802.11-based
wireless interface and with pre-configured policy to prefer Wi-Fi to
cellular access. This so called, "cheap access based on unlicensed
spectrum", is no longer considered an unreliable access, but with all
the available protocol tools and with maturity in technology,
building a reliable broadband service that can meet the committed
service-level agreements is a non-issue.
Matching this evolution is every service provider's desire to offer
Wi-Fi based broadband services; a new business opportunity even for
both fixed and mobile operators. The demand for bandwidth is only
growing with the availability of new smart devices, new technology
applications and with all the content in the Internet. Furthermore,
an increasing percentage of mobile consumption is happening in the
home and so DSL/Cable operators are exploring options to monetize
their existing networks, most with nation-wide footprint, to build a
high-speed Wi-Fi service that can be the basis for offering new
wireless broadband services and for building roaming agreements with
traditional mobile operators, who are unable to meet the mobile
subscriber growth due to the finite licensed spectrum available for
macro-cell deployments. Every residential CPE device that the
operator owns can now be enabled to provide Wi-Fi service and new
community Wi-Fi hotspots can be built in any location where there is
fixed line coverage. A wireless service based on unlicensed
spectrum, and leveraging existing transport is a huge incentive for
operators to enter this new market.
To support these business goals, operators are looking at mobility
architectures for supporting various requirements. Not all
requirements are well understood, and neither are the implications
with the chosen solution approaches for each of those requirements.
The choice of the architecture has an implication on the CPE
evolution and on the core infrastructure feature requirements.
Therefore, the sole purpose and the goal of this document is to
present all the requirements, identify the protocol tools and any
potential gaps. This analysis is important for enabling the network
vendors and the mobile operators to make the right design choices and
leverage the existing tools that the mobility groups in IETF have
already developed and discourage them from adopting proprietary, non-
standard mechanisms or developing redundant alternatives.
Work in progress ...
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2. Conventions and Terminology
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
This document uses the following abbreviations and definitions:
Customer Premises Equipment (CPE)
It is a network device that is located in the Customer premises.
This device is connected to service providers network and defines
the demarcation point between the provider and the customer.
Access Point Name (APN)
Its the name of a packet data network. This APN concept was first
introduced in GPRS by 3GPP to enable legacy Intelligent Networking
(IN) approaches to be applied to the newly deployed IP packet data
services. In roaming deployments, the APN construct was visible
to the visited network and allowed legacy IN charging solutions to
be supported. Defining an application specific APN then allowed
application charging to be supported.
WLAN controller (WLC)
The entity that provides the centralized forwarding, routing
function for the user traffic.
Community Wi-Fi
It is a residential Wi-Fi network where CPEs provide connectivity
to the home user as well as visitors.
home user
The home user is the customer where the CPE is located.
Mobile Gateway
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It is network entity anchoring IP traffic in the mobile core
network. This entity allocates an IP address which is
topologically valid in the mobile network and may act as a
mobility anchor if handover between mobile and Wi-Fi is supported.
3. Deployment Models
Figure 1 illustrates the most common residential and hotspots Wi-Fi
deployment models.
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_----_ _----_ _----_
_( )_ _( )_ _( )_
(Operator-1) (Operator-2) (Operator-3)
(_ _) (_ _) (_ _)
-+-- -+-- '-+--'
+--------+ +--------+ +--------+
| Mobile | | Mobile | | Mobile |
|gateway | |gateway | |gateway |
+--------+ +--------+ +--------+
| | |
+-------------. | .-------------+
| | |
| | |
| | |
| | |
+--------+ _----_
+---+ | | _( )_
|AAA|. . . . . . . | Access |----------( Internet )
+---+ ...... | Aggreg | (_ _)
| . | Gateway| '----'
+--------+ . +--------+
|Web Auth|..... | | |
| Portal | | | +-------------+
+--------+ | | |
| | +-----+
+---------------+ | | AR |
| +-----+ +-----+
+-----+ | WLC | * ---------*
| CPE | | | ( LAN )
|(AR) | +-----+ * ---------*
+-----+ / \ / \
. +----+ +----+ +----+ +----+
/ \ |WiFi| |WiFi| |WiFi| |WiFi|
MN MN | AP | | AP | | AP | | AP |
+----+ +----+ +----+ +----+
Community . .
WiFi user / \ / \
MN MN MN MN
Figure 1: WLAN Service for Retail Model
4. Requirements
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4.1. Subscriber Authentication & Service Authorization
When subscriber attaches to Wi-Fi SP network, the subscriber must
authenticate her identity to the network. The network will offer
service to the subscriber based on the subscriber's identity. The
authentication process should be seamless and support auto sign-in
when possible.
4.2. Location-based Services
In many deployments, there is a need for the mobile operator to
provide differentiated services and policing to the mobile nodes
based on the access network to which they are attached. Policy
systems in mobility architectures such as PCC and ANDSF in 3GPP
system allow configuration of policy rules with conditions based on
the access network information. For example, the service treatment
for the mobile node's traffic may be different when they are attached
to a access network owned by the home operator than when owned by a
roaming partner. The service treatment can also be different based
on the configured Service Set Identifiers (SSID) in case of IEEE
802.11 based access networks. Other examples of location services
include the operator's ability to display a location specific Web
Page, or apply tariff based on the location.
4.3. Local Services Access & Internet Traffic Offload
In the integrated access architectures, the mobile node's IP traffic
is always tunneled back from the access network to the mobile gateway
in the home network. However, with the exponential growth in the
mobile data traffic, mobile operators are exploring new ways to
offload some of the IP traffic flows at the nearest access edge where
ever there is an internet peering point, as supposed to carrying it
all the way to the mobility anchor in the home network. Not all IP
traffic need to be routed back to the home network, some of the non-
essential traffic which does not require IP mobility support can be
offloaded at the mobile access gateway in the access network. This
approach provides greater leverage and efficient usage of the mobile
packet core which help lowering transport cost.
IP traffic offload can be managed at the access aggregation gateway
or can also take place at the terminal side. Here, the mobile node
shall play with two IP addresses: an IP address anchored at the Wi-Fi
aggregation gateway for traffic to be offloaded and a second IP
address anchored at the mobile gateway for traffic to be conveyed via
the mobile network. The offload is thus a source address selection
problem and the terminal must be able to distinguish the address
anchored in the mobile network from the address anchored at the Wi-Fi
aggregation gateway.
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4.4. Web-based Authentication Support
Most Public Wireless LAN (PWLAN) deployments today use web-based
authentication for authorizing the user for network access. Web-
based mode of authentication is considered a legacy mode, for its
weak security properties, and there are efforts to replace it with
802.1x-based security mechanisms. However, a very high percentage of
the PWLAN deployments are still using using this authentication mode
and operators are not willing to move away from this mode any time
soon. The reason being, lack of support for 802.1x/EAP support on
the 100's of millions of handsets that are out there, and for the
lack of client software in the laptops running various operating
systems versions. This is forcing the operators to support web-based
authentication.
4.5. Transparent Auto Login (TAL)
In many deployments, there is a need to support Transparent Auto
Login capability. This is essentially an approach for maintaining
Authenticated state for a user, for a duration of time. Once an
authenticated user disconnects and reattaches to the network, the
network should allows instant access without forcing the user to re-
authenticate.
4.6. Multiple WLAN SSID Support
Wi-Fi SP may broadcast multiple SSIDs. For example, Wi-Fi SP A may
partner with Wi-Fi SP B. Both will broadcast the partner's SSID along
with its own SSID. In this scenario, Wi-Fi SP must be able to
execute different policy based on SSID. For example: when a
subscriber attaches to partner's SSID, the Wi-Fi SP should forward
the authentication request to the partner authentication server.
4.7. Multiple Home Network Service (APN) Access
The 3GPP system architecture supports the concept of an Access Point
Name (APN). An APN can identify a particular routing domain and can
be used by 3GPP operators to segment user traffic. APNs are included
in the session establishment signaling sent by 3GPP User Equipments
(UEs), identifying which routing domain they want to be connected to.
Furthermore, 3GPP has defined a system architecture which supports
the ability of a single UE to have simultaneous connectivity to a
plurality of APNs, and be allocated multiple IPv4 addresses and/or
IPv6 prefixes from the network.
There is a need to ensure multiple APN access for a subscriber in the
community Wi-Fi network.
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4.8. CPE Identity and Authorization
There are two known models with respect to CPE roll out. The
consumer may purchase a device off the shelf and plugin to the
network, or the operator at the time of service creation may have
shipped a new device with the pre-provisioned service configuration.
In either case, the operator needs to be able to identify the device
based on the IP address and associate that to a given location.
The Wi-Fi network performs access control of UEs, via the CPE acting
as AAA supplicant. As a result, the mobile network does not
authenticate directly the user but shall trust the CPE performing the
authentication.
4.9. Mobility within the WLAN Access Network
The mobile node should have the ability to roam within the wi-fi
domain. Depending on the deployment model, the mobile node may roam
across across different IP subnets. To survive to such handover,
some applications (e.g. VPN, streaming) need the IP address to be
preserved.
A WLAN network may include a large number of Wi-Fi base stations. In
some occasions, two or more Wi-Fi base stations may cover the same
area. When a subscriber receives Wi-Fi service in this overlapped
area, the device may bounce between different base stations. This is
typical Proximity problem. In this scenario, it is important for the
WLAN to offer mobility to the subscriber as such the subscriber can
continue the services without changing its IP address.
4.10. Mobility across WLAN and Macro Access
A mobile node should have the ability to handover from macro network
to the Wi-Fi network and be able to retain IP address configuration
and be able to access the home operator services.
4.11. Differentiated Services for Users behind CPE
Some Wi-Fi SPs enable Wi-Fi base station function on home CPE. A
Wi-Fi enabled home CPE may offer multiple services such as VoIP and
data service for home user. It is important for the Wi-Fi SP to
differentiate services and offer different service policies. For
example, Wi-Fi SP may decide to give higher priority to home
generated packets over public Wi-Fi services.
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4.12. Lawful Intercept (LI)
Lawful Intercept [RFC2119] stands for legally authorized interception
and monitoring of communications to and from a subscriber under
Surveillance by a Law Enforcement Agency. In most of the countries,
there are legal obligations for Service Providers to facilitate the
intercept of any subscriber's communication if requested by law
enforcement agencies. Communications Assistance for Law Enforcement
Act (CALEA), the United States wiretapping law passed in 1994 is an
example for such legal mandates. This section talks about Lawful
Intercept solution requirements that are operators are required to
support when offering WLAN services.
The following are the key considerations with respect to supporting
Lawful Intercept capability in Wi-Fi architectures.
o The operator should have the ability to capture IP traffic from
any of the mobile nodes for which the operator is offering Wi-Fi
services.
o The ability to identify the Geo-location of the mobile node to the
nearest WLAN access point.
o The ability to track the mobile node's roaming within the network,
even when there are no active IP flows.
o The ability to pre-provision Lawful Intercept for an inactive
mobile node so that that the capture of IP traffic can be
initiated anytime new IP flows associated to that mobile node are
detected.
o Lawful Intercept (LI) should be undetectable by the intercept
subject
o Mechanisms should be in place to limit unauthorized personnel from
performing or knowing about lawfully authorized intercepts
o If the information being intercepted is encrypted by the service
provider and the service provider has access to the keys, then the
information should be decrypted before delivery to the Law
Enforcement Agency (LEA) or the encryption keys should be passed
to the Law Enforcement Agency to allow them to decrypt the
information.
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4.13. Charging & Accounting
TBD
4.14. Overlapping IPv4 Address Support
Wi-Fi Service Provider may segment the network into regions. Two
regions may use overlap IPv4 address space. This is particularly
important when the Internet is transitioning to IPv6. The Wi-Fi SP
may not have enough unique public IPv4 addresses to globally address
large number of Wi-Fi device.
4.15. Policy Provisioning
IP traffic offload can be managed at the access aggregation gateway.
In such a case, the mobile gateway can potentially deliver offload
policies (i.e. IP flow selectors identifying the IP flows that need
to be offloaded) to the access aggregation gateway in the access
network.
The offload management can also take place at the terminal side.
Here, the mobile node shall play with two IP addresses: an IP address
anchored at the Wi-Fi aggregation gateway for traffic to be offloaded
and a second IP address anchored at the mobile gateway for traffic to
be conveyed via the mobile network. The offload is thus a source
address selection problem. The mobile gateway can potentially
deliver source address selection policies (i.e. association of IP
flow selectors and IP source address).
A single operator has deployed both a fixed access network and a
mobile access network. In this scenario, the operator may wish a
harmonized QoS management on both accesses. However the fixed access
network does not implement a QoS control framework. So, the operator
may choose to rely on the mobile network, specifying the standard
framework to provide a QoS control, to enforce the QoS policy from
the mobile gateway to the Wi-Fi Access network.
5. Solution Approach
5.1. PMIPv6 MAG in the Residential CPE
5.2. PMIPv6 MAG in the Access Gateway
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6. IANA Considerations
This document does not require any IANA actions.
7. Security Considerations
This specification identifies the requirements for enabling Community
Wi-Fi Services over Residential architectures and the potential
solution approaches for addressing those requirements. The security
analysis for each of those requirements are covered in those
respective sections.
8. Acknowledgements
The authors would like to thank Byju Pularikkal for all the
discussions related to Lawful Interception and the related text.
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.
9.2. Informative References
[I-D.gundavelli-netext-multiple-apn-pmipv6]
Gundavelli, S., Grayson, M., Lee, Y., Deng, H., and H.
Yokota, "Multiple APN Support for Trusted Wireless LAN
Access", draft-gundavelli-netext-multiple-apn-pmipv6-01
(work in progress), February 2012.
[I-D.gundavelli-netext-pmipv6-wlan-applicability]
Gundavelli, S., "Applicability of Proxy Mobile IPv6
Protocol for WLAN Access Networks",
draft-gundavelli-netext-pmipv6-wlan-applicability-02 (work
in progress), October 2011.
[I-D.ietf-netext-access-network-option]
Gundavelli, S., Korhonen, J., Grayson, M., Leung, K., and
R. Pazhyannur, "Access Network Identifier (ANI) Option for
Proxy Mobile IPv6",
draft-ietf-netext-access-network-option-07 (work in
progress), February 2012.
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[I-D.ietf-netext-pmipv6-sipto-option]
Gundavelli, S., Zhou, X., Korhonen, J., and R. Koodli,
"IPv4 Traffic Offload Selector Option for Proxy Mobile
IPv6", draft-ietf-netext-pmipv6-sipto-option-04 (work in
progress), February 2012.
[I-D.liebsch-netext-pmip6-authiwk]
Liebsch, M., Seite, P., and S. Gundavelli, "PMIPv6 inter-
working with WiFi access authentication",
draft-liebsch-netext-pmip6-authiwk-03 (work in progress),
October 2011.
[I-D.liebsch-netext-pmip6-qos]
Seite, P., Liebsch, M., Korhonen, J., Gundavelli, S., and
H. Yokota, "Quality of Service Option for Proxy Mobile
IPv6", draft-liebsch-netext-pmip6-qos-00 (work in
progress), October 2011.
[RFC2663] Srisuresh, P. and M. Holdrege, "IP Network Address
Translator (NAT) Terminology and Considerations",
RFC 2663, August 1999.
[RFC3924] Baker, F., Foster, B., and C. Sharp, "Cisco Architecture
for Lawful Intercept in IP Networks", RFC 3924,
October 2004.
[RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K.,
and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008.
[RFC5844] Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy
Mobile IPv6", RFC 5844, May 2010.
[TS23402] 3GPP, "Architecture enhancements for non-3GPP accesses",
2010.
Authors' Addresses
Sri Gundavelli
Cisco
170 West Tasman Drive
San Jose, CA 95134
USA
Email: sgundave@cisco.com
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Mark Grayson
Cisco
11 New Square Park
Bedfont Lakes, FELTHAM TW14 8HA
ENGLAND
Email: mgrayson@cisco.com
Pierrick Seite
France Telecom - Orange
4, rue du clos courtel BP 91226
Cesson-Sevigne, 35512
France
Email: pierrick.seite@orange-ftgroup.com
Yiu L. Lee
Comcast
One Comcast Center
Philadelphia, PA 19103
U.S.A.
Email: yiu_lee@cable.comcast.com
URI: http://www.comcast.com
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