NETEXT WG R. Pazhyannur
Internet-Draft S. Speicher
Intended status: Standards Track S. Gundavelli
Expires: September 4, 2014 Cisco
J. Korhonen
Broadcom
J. Kaippallimalil
Huawei
March 3, 2014
Extensions to the PMIPv6 Access Network Identifier Option
draft-pazhyannur-netext-civic-location-ani-subopt-02.txt
Abstract
Access Network Identifier (ANI) Mobility option was introduced in
[RFC6757] enabling a MAG to convey information like network
identifier, geo-location, operator-identifier. This specification
extends Access Network Identifier mobility option with sub-options to
carry Civic Location and MAG Group Identifer This specificaton also
defines a ANI update timer sub-option that informs the the LMA when
(and how often) the ANI will be updated.
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 4, 2014.
Copyright Notice
Copyright (c) 2014 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
Pazhyannur, et al. Expires September 4, 2014 [Page 1]
Internet-Draft Extensions to ANI March 2014
(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 . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions and Terminology . . . . . . . . . . . . . . . . . 3
2.1. Conventions . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
3. Protocol Extension . . . . . . . . . . . . . . . . . . . . . 4
3.1. Civic-Location Sub-Option . . . . . . . . . . . . . . . . 4
3.2. MAG Group-Id Sub-Option . . . . . . . . . . . . . . . . . 5
3.3. ANI Update-Timer Sub-Option . . . . . . . . . . . . . . . 5
4. Protocol Considerations . . . . . . . . . . . . . . . . . . . 6
4.1. MAG Considerations . . . . . . . . . . . . . . . . . . . 6
4.2. LMA Considerations . . . . . . . . . . . . . . . . . . . 7
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
8.1. Normative References . . . . . . . . . . . . . . . . . . 9
8.2. Informative References . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
[RFC6757] introduced the Access Network Identifier (ANI) mobility
Option. This enabled a MAG to provide the Network Identifier, Geo-
Location, and Operator-Identifier sub options. When the access
network is WLAN, the Network Identiifer sub option may contain SSID,
and BSSID of the Access Point (AP), the Geo-Location may contain the
latitude/longitude of the AP, and the Operator-Identifier may contain
the realm of the operator managing the WLAN. The MAG sends the above
information is sent to the LMA. The LMA may use this information to
determine access network specific policies (in terms of QoS, DPI,
etc). Further, the LMA may make this information available to
location based applications.
While the above mentioned sub-options provide a rich set of
information, in this document we describe the need for extending the
ANI sub options, especially relevant for WLAN deployments. In many
deployments (especially indoor AP deployments), it is difficult to
provide Geo-spatial coordinates of APs. However, for many location
Pazhyannur, et al. Expires September 4, 2014 [Page 2]
Internet-Draft Extensions to ANI March 2014
based applications the civic location is sufficient. This motivates
the need for a ANI civic-location sub-option. In many deployments,
operators tend to create groups of APs into "AP-Groups". These
groups have a group identifier. The group-identifier is used a proxy
for coarse location (such as floor of a building, or a small
building). The group identifier may also be used to provide a common
policy (e.g., QoS, charging, DPI) for all APs in that group. This
specification provides a sub-option for the MAG to convey a group-
identifier to the LMA. (The provisioning of the group-identifier is
outside the scope of this specification and is typically done via a
configuration mechanism such as CLI (Command line Interface), CAPWAP
[RFC5416], etc. This document also provides a new sub-option that
determines how often the MAG will update the ANI. In typical
deployments, it is expected that the MAG will update the ANI as soon
as it changes. This is certainly true when the MAG is co-located
with the AP. When a client roams from one AP to another AP, the MAG
on the roamed AP will provide the new ANI (for example the network
identifier and Geo-location of the new AP). However, if the MAG is
co-located with an Access Controller (also known as Wireless LAN
Controller), then a client roaming from one AP to another AP may not
neceesarily require an ANI update. This leads to stale ANI
information at the LMA. To cover both cases, ANI is always fresh,
ANI may be stale, we introduce a new ANI Update Timer option. This
enables the MAG to inform the LMA when and how often the MAG will
update the ANI. The MAG sends an ANI update only if the ANI Update
Timer has expired and the ANI values have changed since the last ANI
update. Consequently, this enables the LMA to determine whether i
the ANI is stale or not and when to expect an update. The LMA can
use ANI update Timer option to set the maximum frequency at which it
wants to receive ANI updates. This may be particularly useful in
environments where a MAG covers a large number of Wi-Fi APs and there
is high client mobility between the APs (for example in a stadium Wi-
Fi deployment).
[RFC6757] provides ANI sub-options to carry geo-location information.
In this document we provide additional sub-options to carry civic-
location, and AP-Group identifer. This documents also defines an ANI
sub-option to enable a MAG to communicate how often the MAG will
update the ANI information.
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].
Pazhyannur, et al. Expires September 4, 2014 [Page 3]
Internet-Draft Extensions to ANI March 2014
2.2. Terminology
All the mobility related terms used in this document are to be
interpreted as defined in [RFC5213] and [RFC5844].
3. Protocol Extension
3.1. Civic-Location Sub-Option
The Civic-Location is a mobility sub-option carried in the Access
Network Identifier option defined in [RFC6757]. This sub-option
carries the Civic Location information of the mobile node as known to
the MAG. The format of this option is defined below.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ANI Type=IANA | ANI Length | Format | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Civic Location ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Network-Identifier Sub-option
ANI Type: <IANA-1>
ANI Length: Total length of this sub option in octets, excluding the
ANI Type and ANI length fields.
Format: This specifies the encoding format of the Civic location.
Two values are defined in this specification.
0: This value denotes Binary Encoding. The location format is
based on the encoding format defined in Section 3.1 of
[RFC4776], whereby the first 3 octets are not put into the
Civic Location field (i.e., the code for the DHCP option, the
length of the DHCP option, and the 'what' element are not
included).
1: This value denotes XML Encoding. This is specified in the
Presence Information Data Format Location Object [RFC5139].
Civic Location: This field will contain the Civic Location. The
format (encoding) type is specified in the format field of this
sub option. Note that the length shall not exceed 252 bytes.
Pazhyannur, et al. Expires September 4, 2014 [Page 4]
Internet-Draft Extensions to ANI March 2014
3.2. MAG Group-Id Sub-Option
The MAG Group Identifier is a mobility sub-option carried in the
Access Network Identifier option defined in [RFC6757]. The MAG Group
Identifier identifies the group affiliation of the MAG within that
Proxy Mobile IPv6 domain. When the MAG is configured with a group
identifier, the MAG may send its group-id in the PBU. (The
configuration of this group identifier is outside the scope of this
specification. The usage of the group identifier by the LMA is left
to implementation. ) The format of this option is defined below.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ANI Type=IANA | ANI Length | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Group Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: MAG Group-Identifier Sub-option
ANI Type: <IANA-2>
ANI Length: Total length of this sub option in octets, excluding the
ANI Type and ANI length fields. The value is always 6.
Reserved: MUST be set to zero when sending and ignored when
received.
Group Identifier:
3.3. ANI Update-Timer Sub-Option
The ANI Update Timer is a mobility sub-option carried in the ANI
option defined in [RFC6757]. Section 4 describes how the MAG and LMA
may use this sub option.
Pazhyannur, et al. Expires September 4, 2014 [Page 5]
Internet-Draft Extensions to ANI March 2014
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ANI Type=IANA | ANI Length | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Update-Timer |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Network-Identifier Sub-option
ANI Type: <IANA-3>
ANI Length: Total length of this sub option in octets, excluding the
ANI Type and ANI length fields is always 6.
Reserved: MUST be set to zero when sending and ignored when
received.
Update-Timer: Update-Timer is a 16 bit unsigned integer. It
indicates the time in seconds before the MAG sends an update value
of ANI mobility options. A value of 0 indicates that the MAG will
send an updated ANI mobility option as soon as it discovers a
change in ANI values.
4. Protocol Considerations
The following considerations apply to the LMA and the MAG.
4.1. MAG Considerations
o The conceptual Binding Update List entry data structure maintained
by the mobile access gateway, described in Section 6.1 of
[RFC5213], MUST be extended to store the access-network-related
information elements associated with the current session.
Specifically, the following parameters MUST be defined:
* Civic Location
* MAG Group-Id
* ANI Update-Timer
o ANI Update Timer Considerations: The MAG sets the update timer
when it sends a PBU with the ANI Update Timer sub option. When
the update-timer expires, if the ANI options have changed, the MAG
sends an PBU with update ANI. if the ANI options have not
Pazhyannur, et al. Expires September 4, 2014 [Page 6]
Internet-Draft Extensions to ANI March 2014
changed, the MAG does not send a PBU. It sends an PBU with
updated ANI values only when the ANI changes. The Update timer is
reset when the PBU is sent. When the Update-Timer Sub option is
carried in a PBU, it is considered as a proposed value for the
update-timer. When the Update-Timer sub option is carried in a
PBA, then it is considered as an accepted value for the update-
timer. If the MAG does not receive a update-timer sub option in
PBA (in response to sending the sub-option in the PBU), then MAG
behavior with respect to updating the ANI values is left to
implementation choices.
4.2. LMA Considerations
o The conceptual Binding Cache entry data structure maintained by
the local mobility anchor, described in Section 5.1 of [RFC5213],
MUST be extended to store the access-network-related information
elements associated with the current session. Specifically, the
following parameters MUST be defined:
* Civic Location
* MAG Group-Id
* ANI Update-Timer
o On receiving a Proxy Binding Update message [RFC5213] from a
mobile access gateway with the Access Network Information option,
the local mobility anchor must process the option and update the
corresponding fields in the Binding Cache entry. If the option is
not understood by that LMA implementation, it will skip the
option.
o If the local mobility anchor understands/supports the Access
Network Identifier mobility sub-options defined in this
specification, then the local mobility anchor MUST echo the Access
Network Identifier mobility option with the specific sub-option(s)
that it accepted back to the mobile access gateway in a Proxy
Binding Acknowledgement. The Access Network Identifier sub-
options defined in this specification MUST NOT be altered by the
local mobility anchor with the exception of the ANI Update Timer
sub-option.
o ANI Update Timer Considerations: When the LMA receives this sub
option, it may choose to change the value of this sub-option in
the PBA. For example, if the LMA does not want to receive
frequent updates (as indicated by the timer value) it may choose
to increase the value. Similarly, if the LMA needs to receive ANI
Pazhyannur, et al. Expires September 4, 2014 [Page 7]
Internet-Draft Extensions to ANI March 2014
updates as soon as possible then it may set the value to zero (0)
in the PBA.
5. IANA Considerations
This document requires the following IANA action.
o Action-1: This specification defines a new Access Network
Identifier sub-option called Civic Location Sub-option. This
mobility sub-option is described in Section 3.1 and this sub-
option can be carried in Access Network Identifier mobility
option. The type value <IANA-1> for this sub-option needs to be
allocated from the registry "Access Network Information (ANI) Sub-
Option Type Values". RFC Editor: Please replace <IANA-1> in
Section 3.1 with the assigned value, and update this section
accordingly.
o Action-2: This specification defines a new Access Network
Identifier sub-option called MAG Group Identifier Sub-option.
This mobility sub-option is described in Section 3.2 and this sub-
option can be carried in Access Network Identifier mobility
option. The type value <IANA-2> for this sub-option needs to be
allocated from the registry "Access Network Information (ANI) Sub-
Option Type Values". RFC Editor: Please replace <IANA-2> in
Section 3.2 with the assigned value, and update this section
accordingly.
o Action-3: This specification defines a new Access Network
Identifier sub-option called ANI-Update-Timer Sub-option. This
sub-option is described in Section 3.3 and this sub-option can be
carried in Access Network Identifier mobility option. The type
value <IANA-3> for this sub-option needs to be allocated from the
registry "Access Network Information (ANI) Sub-Option Type
Values". RFC Editor: Please replace <IANA-3> in Section 3.3 with
the assigned value, and update this section accordingly.
6. Security Considerations
The Civic Location and the ANI-Update-Frequency sub-Options defined
in this specification are to be carried in the Access Network
Identifier option defined in [RFC6757]. This sub-option is carried
in Proxy Binding Update and Proxy Binding Acknowledgement messages.
This sub-option is carried like any other Access Network Identifier
sub-option as defined in [RFC6757]. Therefore, it inherits from
[RFC5213] and [RFC6757], its security guidelines and does not require
any additional security considerations.
Pazhyannur, et al. Expires September 4, 2014 [Page 8]
Internet-Draft Extensions to ANI March 2014
The Civic Location sub-option carried in the Access Network
Information option exposes the civic location of the network to which
the mobile node is attached. This information is considered to be
very sensitive, so care must be taken to secure the Proxy Mobile IPv6
signaling messages when carrying this sub-option. The base Proxy
Mobile IPv6 specification [RFC5213] specifies the use of IPsec for
securing the signaling messages, and those mechanisms can be enabled
for protecting this information. Operators can potentially apply
IPsec Encapsulating Security Payload (ESP) with confidentiality and
integrity protection for protecting the location information.
Access-network-specific information elements that the mobile access
gateway sends may have been dynamically learned over DHCP or using
other protocols. If proper security mechanisms are not in place, the
exchanged information may be potentially compromised with the mobile
access gateway sending incorrect access network parameters to the
local mobility anchor. This situation may potentially result in
incorrect service policy enforcement at the local mobility anchor and
impact to other services that depend on this access network
information. This threat can be mitigated by ensuring the
communication path between the mobile access gateway and the access
points is properly secured by the use of IPsec, Transport Layer
Security (TLS), or other security protocols.
7. Acknowledgements
TBD
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4776] Schulzrinne, H., "Dynamic Host Configuration Protocol
(DHCPv4 and DHCPv6) Option for Civic Addresses
Configuration Information", RFC 4776, November 2006.
[RFC5139] Thomson, M. and J. Winterbottom, "Revised Civic Location
Format for Presence Information Data Format Location
Object (PIDF-LO)", RFC 5139, February 2008.
[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.
Pazhyannur, et al. Expires September 4, 2014 [Page 9]
Internet-Draft Extensions to ANI March 2014
[RFC6757] Gundavelli, S., Korhonen, J., Grayson, M., Leung, K., and
R. Pazhyannur, "Access Network Identifier (ANI) Option for
Proxy Mobile IPv6", RFC 6757, October 2012.
8.2. Informative References
[RFC5415] Calhoun, P., Montemurro, M., and D. Stanley, "Control And
Provisioning of Wireless Access Points (CAPWAP) Protocol
Specification", RFC 5415, March 2009.
[RFC5416] Calhoun, P., Montemurro, M., and D. Stanley, "Control and
Provisioning of Wireless Access Points (CAPWAP) Protocol
Binding for IEEE 802.11", RFC 5416, March 2009.
Authors' Addresses
Rajesh S. Pazhyannur
Cisco
170 West Tasman Drive
San Jose, CA 95134
USA
Email: rpazhyan@cisco.com
Sebastian Speicher
Cisco
Richtistrasse 7
Wallisellen, Zurich 8304
Switzerland
Email: sespeich@cisco.com
Sri Gundavelli
Cisco
170 West Tasman Drive
San Jose, CA 95134
USA
Email: sgundave@cisco.com
Pazhyannur, et al. Expires September 4, 2014 [Page 10]
Internet-Draft Extensions to ANI March 2014
Jouni Korhonen
Broadcom
Porkkalankatu 24
Helsinki FIN-00180
Finland
Email: jouni.nospam@gmail.com
John Kaippallimalil
Huawei
5340 Legacy Drive, Suite 175
Plano, Texas 75024
USA
Email: john.kaippallimalil@huawei.com
Pazhyannur, et al. Expires September 4, 2014 [Page 11]