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 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 23, 2015. Copyright Notice Copyright (c) 2015 IETF Trust and the persons identified as the document authors. All rights reserved. Pazhyannur, et al. Expires September 23, 2015 [Page 1] Internet-Draft Extensions to ANI March 2015 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. Pazhyannur, et al. Expires September 23, 2015 [Page 2] Internet-Draft Extensions to ANI March 2015 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. Pazhyannur, et al. Expires September 23, 2015 [Page 3] Internet-Draft Extensions to ANI March 2015 [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 Pazhyannur, et al. Expires September 23, 2015 [Page 4] Internet-Draft Extensions to ANI March 2015 ANI Type: 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 Pazhyannur, et al. Expires September 23, 2015 [Page 5] Internet-Draft Extensions to ANI March 2015 ANI Type: 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: 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 Pazhyannur, et al. Expires September 23, 2015 [Page 6] Internet-Draft Extensions to ANI March 2015 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 Pazhyannur, et al. Expires September 23, 2015 [Page 7] Internet-Draft Extensions to ANI March 2015 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 Pazhyannur, et al. Expires September 23, 2015 [Page 8] Internet-Draft Extensions to ANI March 2015 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 for this sub option needs to be allocated from the registry "Access Network Information (ANI) Sub- Option Type Values". RFC Editor: Please replace 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 for this sub option needs to be allocated from the registry "Access Network Information (ANI) Sub- Option Type Values". RFC Editor: Please replace 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 for this sub option needs to be allocated from the registry "Access Network Information (ANI) Sub-Option Type Values". RFC Editor: Please replace 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 Pazhyannur, et al. Expires September 23, 2015 [Page 9] Internet-Draft Extensions to ANI March 2015 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. Pazhyannur, et al. Expires September 23, 2015 [Page 10] Internet-Draft Extensions to ANI March 2015 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 Pazhyannur, et al. Expires September 23, 2015 [Page 11] Internet-Draft Extensions to ANI March 2015 John Kaippallimalil Huawei 5340 Legacy Drive, Suite 175 Plano, Texas 75024 USA Email: john.kaippallimalil@huawei.com Pazhyannur, et al. Expires September 23, 2015 [Page 12]