



NETEXT WG                                                  R. Pazhyannur
Internet-Draft                                               S. Speicher
Updates: 6757 (if approved)                                S. Gundavelli
Intended status: Standards Track                           Cisco Systems
Expires: September 23, 2015                                  J. Korhonen
                                                                Broadcom
                                                       J. Kaippallimalil
                                                                  Huawei
                                                          March 22, 2015


       Extensions to the PMIPv6 Access Network Identifier Option
                 draft-ietf-netext-ani-location-09.txt

Abstract

   Access Network Identifier (ANI) Mobility option was introduced in
   Access Network Identifier Option for Proxy Mobile IPv6 (RFC 6757).
   This enables a Mobility Access Gateway (MAG) to convey identifiers
   like network identifier, geolocation, and operator identifier.  This
   specification extends the Access Network Identifier mobility option
   with sub options to carry civic location and MAG group Identifier.
   This specification also defines an ANI Update-Timer sub option that
   determines when and how often the ANI option 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
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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
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   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 23, 2015.

Copyright Notice

   Copyright (c) 2015 IETF Trust and the persons identified as the
   document authors.  All rights reserved.





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   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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions and Terminology . . . . . . . . . . . . . . . . .   4
     2.1.  Conventions . . . . . . . . . . . . . . . . . . . . . . .   4
     2.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Protocol Extension  . . . . . . . . . . . . . . . . . . . . .   4
     3.1.  Civic Location Sub-Option . . . . . . . . . . . . . . . .   4
     3.2.  MAG Group identifier Sub-Option . . . . . . . . . . . . .   5
     3.3.  ANI Update-Timer Sub-Option . . . . . . . . . . . . . . .   6
   4.  Protocol Considerations . . . . . . . . . . . . . . . . . . .   6
     4.1.  MAG Considerations  . . . . . . . . . . . . . . . . . . .   6
     4.2.  LMA Considerations  . . . . . . . . . . . . . . . . . . .   8
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   8
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  10
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  10
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  11
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  11

1.  Introduction

   Access Network Identifier (ANI) Option for Proxy Mobile IPv6
   [RFC6757] introduced the Access Network Identifier (ANI) mobility
   Option.  This enabled a Mobility Access Gateway (MAG) to provide the
   Network Identifier, geolocation, and Operator-Identifier sub options.
   When the access network is WLAN, the Network Identifier sub option
   may contain Service Set Identifier (SSID) and Basic Service Set
   Identifier (BSSID) of the Access Point (AP), the geolocation of the
   AP, and the Operator-Identifier may contain the realm of the operator
   managing the WLAN.  The MAG sends the above information to the Local
   Mobility Anchor (LMA).  The LMA may use this information to determine
   access network specific policies (in terms of Quality of Service
   (QoS), Deep Packet Inspection (DPI), etc.).  Further, the LMA may
   make this information available to location based applications.





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   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, particularly useful in WLAN deployments.  In WLAN
   deployments (especially indoor AP deployments), it is difficult to
   provide Geo-spatial coordinates of APs.  At the same time, for many
   location 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
   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), or via
   CAPWAP ([RFC5415], [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 (or
   sometimes referred to as the target) AP will provide the new ANI (for
   example the network identifier and geolocation of the new AP).
   However, if the MAG is co-located with an Access Controller (also
   known as Wireless LAN Controller (WLC)), then a client roaming from
   one AP to another AP does not necessarily perform an ANI update.  The
   WLC handles client mobility between APs and as a result, intra-WLC
   mobility is hidden from the LMA.  In such deployments, the
   information conveyed in the ANI sub-options (e.g. location) becomes
   stale and is only refreshed at the time of lifetime expiry.  The MAG
   could deal with this by sending a Proxy Binding Update (PBU) whenever
   a client moves between APs just for the purpose of updating ANI sub
   option.  Alternately, this draft allows the LMA to determine how
   often it wants to know about the changes in the ANI sub option.  For
   example, in some cases the LMA may not care about ANI sub option
   except at the time of initial binding or in some cases it may care
   about every AP transitions.  The sub option allows LMA to tell the
   MAG the desired update frequency.  As always, mobility events or re-
   registration events will update ANI sub options.The LMA can use ANI
   Update-Timer option to set the maximum frequency at which it wants to
   receive ANI updates.  This is 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.  For example, if a LMA does not want ANI updates any more
   often than 100 seconds, then it can propose 100 seconds as the value
   for ANI Update-Timer.



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   [RFC6757] provides ANI sub options to carry geolocation information.
   In this document we provide additional sub options to carry civic
   location, and group identifier.  This document 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].

2.2.  Terminology

   All the mobility related terms used in this document are to be
   interpreted as defined in [RFC5213] and [RFC5844].

   Civic Location: There are two common ways to identify the location of
   an object, either through geospatial coordinates or by so-called
   civic addresses.  Geospatial coordinates indicate longitude,
   latitude, and altitude, while civic addresses indicate a street
   address or sometimes the location within a building (such as a room
   number).  Civic location refers to the civic address.

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-1|  ANI Length   |   Format      | Reserved      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            civic location                                     ~
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



                  Figure 1: Network-Identifier Sub-option




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   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.
      The value 0 is defined in this specification as described below.
      The remaining values (1 through 255) are reserved.

         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).

   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 253 bytes./>.

3.2.  MAG Group identifier 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.  The group identifier is not assumed to be
   globally unique, across different network operators.  However, group
   identifier should be unique within an operator network.  In domains
   spanning multiple operators it is recommended that the operator
   identifier sub option (defined in [RFC6757]) be used in addition to
   group identifier sub option to ensure uniqueness.  When the MAG is
   configured with a group identifier, the MAG should send its group
   identifier in the PBU.  (The configuration of this identifier is
   outside the scope of this specification.  The usage of the identifier
   by the LMA is left to implementation.)  The format of this sub 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-2|  ANI Length   |  group identifier             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



                 Figure 2: MAG group identifier Sub-option




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   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 2.

   group identifier:  This is a 2 octet unsigned integer value assigned
      to a group of MAGs.

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
   use this sub option.


    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-3|  ANI Length   |       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 2.

   Update-Timer:  Update-Timer is a 16 bit unsigned integer.  The unit
      of time is seconds.  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.  A non-zero value indicates that the MAG may not send
      ANI values immediately after they have changed but rather send ANI
      updates when the Update-Timer expires.

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], is extended to store the access-network-related




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      information elements associated with the current session.
      Specifically, the following parameters are defined:

      *  civic location

      *  MAG group identifier

      *  ANI Update-Timer

   o  If the mobile access gateway is configured to support the Access
      Network Information sub options defined in this specification, it
      includes this option with the specific sub options in all PBU
      messages (including PBUs for lifetime extension and for
      deregistration) that it sends to the LMA.  The Access Network
      Information option is constructed as specified in Section 3.

   o  ANI Update-Timer Considerations: The MAG sets the Update-Timer
      based on an exchange of timer values with the LMA.  When the
      Update-Timer Sub option is carried in a PBU, it is considered as a
      proposed value for the Update-Timer.  The LMA may change the value
      of the Update-Timer received in the PBU.  When the LMA provided
      value for the Update-Timer is different than what is sent by the
      MAG, the MAG should use the LMA provided value.  If the MAG does
      not receive an Update-Timer sub option in PBA (in response to
      sending the sub option in the PBU), then MAG behavior is in
      accordance to [RFC6757].  When ANI parameters of a mobility
      session change, the MAG checks whether the Update-Timer has
      expired.  If the Update-Timer has expired, the MAG sends a PBU
      with the ANI option.  The ANI option reflects the updated access
      network parameters for that mobility session.  If the Update-Timer
      has not expired, the MAG does not send a PBU.  When the Update-
      Timer for a mobility session expires, the MAG checks whether the
      ANI parameters have changed.  If the parameters have changed from
      the last reported values, the MAG sends a PBU with ANI option.  If
      the parameters have not changed, the MAG does not send a PBU (and
      the Update-Timer remains expired).  Note that the MAG may send a
      PBU even before the Update-Timer expires.  This could be, for
      example, to initiate a QoS service request to the LMA (see
      [RFC7222]).  In such cases, the MAG must reset the Update-Timer
      when it sends a PBU.

   o  If the mobile access gateway had any of the Access Network
      Information mobility options included the PBU sent to a LMA, then
      the PBA received from the LMA should contain the Access Network
      Information mobility option with the specific sub options.  If the
      mobile access gateway receives a PBA with a successful Status
      Value but without an Access Network Information mobility option,
      then the mobile access gateway may log the event and, based on its



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      local policy, even proceed to terminate the mobility session.  In
      this case, the mobile access gateway knows the LMA does not
      understand the Access Network Information mobility option.

4.2.  LMA Considerations

   o  The conceptual Binding Cache entry data structure maintained by
      the LMA, described in Section 5.1 of [RFC5213], is extended to
      store the access-network-related information elements associated
      with the current session.  Specifically, the following parameters
      are defined:

      *  civic location

      *  MAG group identifier

      *  ANI Update-Timer

   o  On receiving a PBU message from a MAG with the ANI option, the LMA
      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 and process the PBU
      without these options.

   o  If the received PBU message does not include the Access Network
      Information option, then the mobility session associated with that
      PBU is updated to remove any access network information elements.

   o  If the LMA understands/supports the Access Network Identifier
      mobility sub options defined in this specification, then the LMA
      echoes the Access Network Identifier mobility option with the
      specific sub option(s) that it accepted back to the mobile access
      gateway in a PBA.  The civic location and group identifier sub
      options defined in this specification should not be altered by the
      LMA.  The LMA may change the value of the Update-Timer sub option.
      It may choose to either echo the same value, or increase or
      decrease the timer value.  For example, if the LMA does not want
      to receive frequent updates (as implied by the timer value) it may
      choose to increase the value.  Similarly, if the LMA needs to
      receive ANI 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



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      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 sub option defined in this specification is
   carried in the Access Network Identifier option defined in [RFC6757].
   This sub option is carried in PBU and PBA 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.

   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.  The
   other way to protect the sensitive location information of network



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   users is of course to not send it in the first place.  Users of the
   civic location sub option should provision location values with the
   highest possible level of granularity, e.g., to the province or city
   level, rather than provisioning specific addresses.

   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 between the MAG and LMA may be compromised.
   This situation may result in incorrect service policy enforcement at
   the LMA 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

   This document benefited considerably from the numerous improvements
   proposed by Kent Leung.

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.

   [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.

   [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.

   [RFC7222]  Liebsch, M., Seite, P., Yokota, H., Korhonen, J., and S.
              Gundavelli, "Quality-of-Service Option for Proxy Mobile
              IPv6", RFC 7222, May 2014.






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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 Systems
   170 West Tasman Drive
   San Jose, CA 95134
   USA

   Email: rpazhyan@cisco.com


   Sebastian Speicher
   Cisco Systems
   Richtistrasse 7
   Wallisellen, Zurich  8304
   Switzerland

   Email: sespeich@cisco.com


   Sri Gundavelli
   Cisco Systems
   170 West Tasman Drive
   San Jose, CA  95134
   USA

   Email: sgundave@cisco.com


   Jouni Korhonen
   Broadcom
   Porkkalankatu 24
   Helsinki  FIN-00180
   Finland

   Email: jouni.nospam@gmail.com





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   John Kaippallimalil
   Huawei
   5340 Legacy Drive, Suite 175
   Plano, Texas  75024
   USA

   Email: john.kaippallimalil@huawei.com












































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