ECRIT H. Schulzrinne Internet-Draft Columbia University Intended status: Experimental H. Tschofenig Expires: April 29, 2010 Nokia Siemens Networks October 26, 2009 Synchronizing Location-to-Service Translation (LoST) Protocol based Service Boundaries and Mapping Elements draft-ietf-ecrit-lost-sync-08.txt Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 29, 2010. Copyright Notice Copyright (c) 2009 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 in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Schulzrinne & Tschofenig Expires April 29, 2010 [Page 1] Internet-Draft LoST Sync October 2009 Abstract The Location-to-Service Translation (LoST) protocol is an XML-based protocol for mapping service identifiers and geodetic or civic location information to service URIs and service boundaries. In particular, it can be used to determine the location-appropriate Public Safety Answering Point (PSAP) for emergency services. The main data structure, the element, used for encapsulating information about service boundaries is defined in the LoST protocol specification and circumscribes the region within which all locations map to the same service Uniform Resource Identifier (URI) or set of URIs for a given service. This document defines an XML protocol to exchange these mappings between two nodes. This mechanism is designed for the exchange of authoritative elements between two entities. Exchanging cached elements, i.e. non-authoritative elements, is possible but not envisioned. In any case, this document can also be used without the LoST protocol even though the format of the element is re-used from the LoST specification. Schulzrinne & Tschofenig Expires April 29, 2010 [Page 2] Internet-Draft LoST Sync October 2009 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 10 3. Querying for Mappings with a / Exchange . . . . . . . . . . . . . . . . 11 3.1. Behavior of the LoST Sync Source . . . . . . . . . . . . . 11 3.2. Behavior of the LoST Sync Source . . . . . . . . . . . . . 11 3.3. Examples . . . . . . . . . . . . . . . . . . . . . . . . . 12 4. Pushing Mappings via and . . . . . . . . . . . . . . . . . . . . 14 4.1. Behavior of the LoST Sync Source . . . . . . . . . . . . . 14 4.2. Behavior of the LoST Sync Destination . . . . . . . . . . 14 4.3. Example . . . . . . . . . . . . . . . . . . . . . . . . . 15 5. Transport . . . . . . . . . . . . . . . . . . . . . . . . . . 18 6. RelaxNG . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 7. Security Considerations . . . . . . . . . . . . . . . . . . . 21 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 8.1. Content-type registration for 'application/lostsync+xml' . . . . . . . . . . . . . . . . 22 8.2. LoST Sync Relax NG Schema Registration . . . . . . . . . . 23 8.3. LoST Synchronization Namespace Registration . . . . . . . 23 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 25 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 26 10.1. Normative References . . . . . . . . . . . . . . . . . . . 26 10.2. Informative References . . . . . . . . . . . . . . . . . . 26 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 27 Schulzrinne & Tschofenig Expires April 29, 2010 [Page 3] Internet-Draft LoST Sync October 2009 1. Introduction The LoST (Location-to-Service Translation) protocol [RFC5222] maps service identifiers and geodetic or civic location information to service URIs. The main data structure, the element, used for encapsulating information about service boundaries is defined in the LoST protocol specification and circumscribes the region within which all locations map to the same service Uniform Resource Identifier (URI) or set of URIs for a given service. This mechanism is designed for the exchange of authoritative elements between two entities (the LoST Sync source and the LoST Sync destination). The LoST Sync mechanism can, for example, be used in the LoST architecture, as specified in the [RFC5582]. There, LoST servers act in different roles that cooperate to provide an ubiquitous, globally scalable and resilient mapping service. In the LoST mapping architecture, LoST servers can peer, i.e., have an on-going data exchange relationship. Peering relationships are set up manually, based on local policies. A server can peer with any number of other servers. Forest guides peer with other forest guides; resolvers peer with forest guides and other resolvers (in the same cluster); authoritative mapping servers peer with forest guides and other authoritative servers, either in the same cluster or above or below them in the tree. Authoritative mapping servers push coverage regions "up" the tree, i.e., from child nodes to parent nodes. The child informs the parent of the geospatial or civic region that it covers for a specific service. Consider a hypothetical deployent of LoST in two countries, we call them Austria and Finland. Austria, in our example, runs three authoritative LoST servers labeled as 'East', 'West' and 'Vienna' whereby the former two cover the entire country expect for Vienna, which is covered by a separate LoST server. There may be other caching LoST servers run by ISPs, universities, and VSPs but they are not relevant for this illustration. Finland, on the other hand, decided to only deploy a single LoST server that also acts as a Forest Guide. For this simplistic illustration we assume that only one service is available, namely 'urn:service:sos' since otherwise the number of stored mappings would have to be multiplied by the number of used services. Figure 1 shows the example deployment. Schulzrinne & Tschofenig Expires April 29, 2010 [Page 4] Internet-Draft LoST Sync October 2009 +---LoST-Sync-->\\ //<--LoST-Sync----+ | ----- | | | \/ \/ ----- ----- // \\ // \\ / \ / \ | Forest | | Forest | | Guide | | Guide | | Austria | | Finland \ / \ / +--------->\\ //<--------+ \\ // | ----- | ----- | /\ | | LoST | LoST //------\\ Sync LoST Sync |Co-Located| | Sync | | LoST | \/ | \/ | Server | //----\\ \/ //----\\ \\------// | LoST | //----\\ | LoST | | Server | | LoST | | Server | | (East) | | Server | |(Vienna)| \\----// | (West) | \\----// \\----// Figure 1: LoST Deployment Example The configuration of these nodes would therefore be as follows: Forest Guide Austria: This forest guide would contain mappings for the three authoritative LoST servers (East, West and Vienna) describing what area they are responsible for. Note that each mapping would contain a service URN and these mappings point to LoST servers rather than to PSAPs or ESRPs. LoST Server 'East': This LoST server would contain all the mappings to PSAPs covering one half of the country. Additionally, the LoST server aggregates all the information it has and provides an abstracted view towards the Forest Guide indicating that it is responsible for a certain area (for a given service, and for a given location profile). Such a mapping would have the following structure: Schulzrinne & Tschofenig Expires April 29, 2010 [Page 5] Internet-Draft LoST Sync October 2009 LoST Server 'East' urn:service:sos ... ..... list of coordinates for boundary of LoST server 'East' ... Figure 2: Forest Guide Austria Mapping Example As it can be seen in this example there the element is left empty and the 'source' attribute is used to indicate the identity of the LoST server, namely "east-austria.lost-example.com". The above-shown mapping is what is the LoST server "east- austria.lost-example.com" provides to the Austrian Forest Guide. LoST Server 'West': This LoST server would contain all the mappings to PSAPs covering the other half of the country. LoST Server 'Vienna': This LoST server would contain all the mappings to PSAPs in the area of Vienna. Forest Guide Finland: In our example we assume that Finland would deploy a single ESRP for the entire country as their IP-based emergency services solution. There is only a single LoST server and it is co-located with the Forest Guide, as shown in Figure 1. The mapping data this FG would distribute via LoST sync is shown in Figure 3. Schulzrinne & Tschofenig Expires April 29, 2010 [Page 6] Internet-Draft LoST Sync October 2009 Finland ESRP urn:service:sos FI Figure 3: Forest Guide Finland Mapping Example An example mapping stored at the co-located LoST server is shown in Figure 4. Finland ESRP urn:service:sos FI sip:esrp@finland-example.com xmpp:esrp@finland-example.com 112 Figure 4: Forest Guide Finland / Co-Located LoST Server Mapping Example The LoST sync mechanism described in this document could be run between the two Forest Guides. Thereby, the three mappings stored in the Austria FG are sent to the FG Finland and a single mapping in the FG Finland is sent to the FG Austria. Additionally, the three Austrian LoST servers could utilize LoST sync to inform the Austrian FG about their boundaries. These three authoritative LoST servers in Schulzrinne & Tschofenig Expires April 29, 2010 [Page 7] Internet-Draft LoST Sync October 2009 Austria would be responsible to maintain their own mapping information. Since the amount of data being exchanged is small and the expected rate of change is low the nodes are configured to always exchange all their mapping information whenever a change happens. This document defines two types of exchanges and those are best described by the exchange between two nodes as shown in Figure 5 and Figure 6. The protocol exchange always runs between a LoST Sync source and a LoST Sync destination. Node A in the examples of Figure 5 and Figure 6 has mappings that Node B is going to retrieve. Node A acts as the source for the data and Node B is the destination. The request allows a LoST Sync source to request mappings from a LoST Sync destination. +---------+ +---------+ | Node B | | Node A | | acting | | acting | | as | | as | | LoST | | LoST | | Sync | | Sync | | Dest. | | Source | +---------+ +---------+ | | | | | | | | |----------------------------->| | | | | |<-----------------------------| | | | | | | Figure 5: Querying for Mappings with a Message Note that in the exchange illustrated in Figure 5 Node B issuing the first request and plays the role of the HTTP/HTTPS client (with HTTP as selected transport) and Node A plays the role of the HTTP/HTTPS server. The exchange allows a LoST Sync source to push mappings to LoST Sync destination. The assumption is being made that Node A and B have previously been configured in a way that they push mappings in such a fashion and that Node A maintains state about the mappings have to be pushed to Node B. No subscribe mechanism is defined in this document that would allow Node B to tell Node A about Schulzrinne & Tschofenig Expires April 29, 2010 [Page 8] Internet-Draft LoST Sync October 2009 what mappings it is interested nor a mechanism for learning to which entities mappings have to be pushed. +---------+ +---------+ | Node A | | Node B | | acting | | acting | | as | | as | | LoST | | LoST | | Sync | | Sync | | Source | | Dest. | +---------+ +---------+ | | | | | | | | |----------------------------->| | | | | |<-----------------------------| | | | | | | Figure 6: Pushing Mappings with a Message Note that in the exchange illustrated in Figure 6 Node A issuing the first request and plays the role of the HTTP/HTTPS client (with HTTP as selected transport) and Node B plays the role of the HTTP/HTTPS server. Schulzrinne & Tschofenig Expires April 29, 2010 [Page 9] Internet-Draft LoST Sync October 2009 2. Terminology 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]. This document reuses terminology introduced by the mapping architecture document [RFC5582]. Throughout this document we use the term LoST Sync source and LoST Sync destination to denote the protocol end points of the exchange. The protocol is referred as LoST Sync within the text. Schulzrinne & Tschofenig Expires April 29, 2010 [Page 10] Internet-Draft LoST Sync October 2009 3. Querying for Mappings with a / Exchange 3.1. Behavior of the LoST Sync Source A LoST Sync destination has two ways to retrieve mapping elements from a LoST Sync source. 1. A mechanisms that is suitable when no mappings are available on the LoST Sync destination is to submit an empty message, as shown in Figure 7. The intent by the LoST Sync destination thereby is to retrieve all mappings from the LoST Sync source. Note that the request does not propagate further to other nodes. 2. In case a LoST Sync destination node has already obtained mappings in previous exchanges then it may want to check whether these mappings have been updated in the meanwhile. The policy when to poll for updated mapping information is outside the scope of this document. The message with one or multiple child element(s) allows to reduce the number of returned mappings to those that have been updated and also to those that are missing. In response to the message the LoST Sync destination waits for the message. In case of a successful response the LoST Sync destination stores the received mappings and determines which mappings to replace. 3.2. Behavior of the LoST Sync Source When a LoST Sync source receives an empty message then all locally available mappings MUST be returned. When a LoST Sync source receives a message with one or multiple child element(s) then it MUST consult with the local mapping database to determine whether any of the mappings of the client is stale and whether there are mappings locally that the client does not yet have. The former can be determined by finding mappings corresponding to the 'source' and 'sourceID' attribut where a mapping with a more recent lastUpdated date exists. Processing a message MAY lead to a successful response in the form of a or an message. Only the , , , errors, defined in [RFC5222], are utilized by this specification. Neither the nor the messages are reused by this message. Schulzrinne & Tschofenig Expires April 29, 2010 [Page 11] Internet-Draft LoST Sync October 2009 3.3. Examples The first example shows an empty message that would retrieve all locally stored mappings at the LoST Sync source. Figure 7: Example of empty message A further example request is shown in Figure 8 and the corresponding response is depicted in Figure 9. In this example a request is made for a specific mapping (with source="authoritative.bar.example" and sourceId="7e3f40b098c711dbb6060800200c9a66") that is more recent than "2006-11-01T01:00:00Z". Figure 8: Example Message The response to the above request is shown in Figure 9. A more recent mapping was available with the identification of source="authoritative.bar.example" and sourceId="7e3f40b098c711dbb6060800200c9a66". Only one mapping that matched source="authoritative.foo.example" was found and returned. Schulzrinne & Tschofenig Expires April 29, 2010 [Page 12] Internet-Draft LoST Sync October 2009 Leonia Police Department urn:service:sos.police US NJ Leonia 07605 sip:police@leonianj2.example.org 911 New York City Police Department urn:service:sos.police 37.775 -122.4194 37.555 -122.4194 37.555 -122.4264 37.775 -122.4264 37.775 -122.4194 sip:nypd@example.com xmpp:nypd@example.com 911 Figure 9: Example Message Schulzrinne & Tschofenig Expires April 29, 2010 [Page 13] Internet-Draft LoST Sync October 2009 4. Pushing Mappings via and 4.1. Behavior of the LoST Sync Source When a LoST Sync source obtains new information that is of interest to its peers, it may push the new mappings to its peers. Configuration settings at both peers decide whether this functionality is used and what mappings are pushed to which other peers. New mappings may arrive through various means, such as a manual addition to the local mapping database, or through the interaction with other entities. Deleting mappings may also trigger a protocol interaction. The LoST Sync source SHOULD keep track to which LoST Sync destination it has pushed mapping elements. If it does not keep state information then it always has to push the complete data set. As discussed in Section 5.1 of [RFC5222], mapping elements are identified by the 'source', 'sourceID' and 'lastUpdated' attributes. A mapping is considered the same if these three attributes match. It is RECOMMENDED not to push the same information to the same peer more than once. A request sent by a LoST Sync source MUST containing one or more elements. To delete a mapping, the content of the mapping is left empty. The node can delete the mapping from its internal mapping database, but has to remember which peers it has distributed this update to. The 'expires' attribute is required, but ignored. If an attempt is made to delete a non-existent mapping, the request is silently ignored. 4.2. Behavior of the LoST Sync Destination When a LoST Sync destination receives a message then a newly received mapping M' MUST replace an existing mapping M if all of the following conditions hold: 1. M'.source equals M.source 2. M'.sourceID' equals M.sourceID 3. M'.lastUpdated is greater than M.lastUpdated If the received mapping M' does not update any existing mapping M then it MUST be added to the local cache as an independent mapping. If a message with an empty element is received then a corresponding mapping has to be determined based on Schulzrinne & Tschofenig Expires April 29, 2010 [Page 14] Internet-Draft LoST Sync October 2009 the 'source', 'sourceID' and 'lastUpdated' attributes. If a mapping has been found then it MUST be deleted. If no mapping can be identified then an response MUST be returned that contains the child element. The element MAY carry a element and MUST contain the element(s) that caused the error. The response to a request is a message. With this specification, a successful response message returns no additional elements, whereas an response is returned in the response message, if the request failed. Only the , , or errors defined in Section 13.1 of [RFC5222], are used. The and messages are not used for this query/response. If the set of nodes that are synchronizing their data does not form a tree, it is possible that the same information arrives through several other nodes. This is unavoidable, but generally only imposes a modest overhead. (It would be possible to create a spanning tree in the same fashion as IP multicast, but the complexity does not seem warranted, given the relatively low volume of data.) 4.3. Example An example is shown in Figure 10. Image a LoST node that obtained two new mappings identified as follows: o source="authoritative.example" sourceId="7e3f40b098c711dbb6060800200c9a66" lastUpdated="2008-11- 26T01:00:00Z" o source="authoritative.example" sourceId="7e3f40b098c711dbb606011111111111" lastUpdated="2008-11- 01T01:00:00Z" These two mappings have to be added to the peer's mapping database. Additionally, the following mapping has to be deleted: o source="nj.us.example" sourceId="123" lastUpdated="2008-11- 01T01:00:00Z" Leonia Police Department urn:service:sos.police US NJ Leonia 07605 sip:police@leonianj.example.org 911 New York City Police Department urn:service:sos.police 37.775 -122.4194 37.555 -122.4194 37.555 -122.4264 37.775 -122.4264 37.775 -122.4194 sip:nypd@example.com xmpp:nypd@example.com 911 Schulzrinne & Tschofenig Expires April 29, 2010 [Page 16] Internet-Draft LoST Sync October 2009 Figure 10: Example Message In response, the peer performs the necessary operation and updates its mapping database. In particular, it will check whether the other peer is authorized to perform the update and whether the elements and attributes contain values that it understands. In our example, a positive response is returned as shown in Figure 11. Figure 11: Example In case that a mapping could not be deleted as requested the following error response might be returned instead. Figure 12: Example Message Schulzrinne & Tschofenig Expires April 29, 2010 [Page 17] Internet-Draft LoST Sync October 2009 5. Transport LoST Sync needs an underlying protocol transport mechanism to carry requests and responses. This document defines an XML protocol over HTTP and over HTTP-over-TLS. Client and server developers are reminded that full support of RFC 2616 HTTP facilities is expected. If clients or servers re-implement HTTP, rather than using available servers or client code as a base, careful attention must be paid to full interoperability. Other transport mechanisms are left to future documents. The selection of the transport mechanism will in most cases be determined through manual configuration although the usage of the U-NAPTR application defined in the LoST specification is possible. In protocols that support content type indication, LoST Sync uses the media type application/lostsync+xml. When using HTTP [RFC2616] and HTTP-over-TLS [RFC2818], LoST Sync messages use the HTTP POST method. The HTTP request MUST use the Cache-Control response directive "no-cache" to HTTP-level caching even by caches that have been configured to return stale responses to client requests. All LoST Sync responses, including those indicating a LoST warning or error, are carried in 2xx responses, typically 200 (OK). Other 2xx responses, in particular 203 (Non-authoritative information) may be returned by HTTP caches that disregard the caching instructions. 3xx, 4xx and 5xx HTTP response codes indicates that the HTTP request itself failed or was redirected; these responses do not contain any LoST Sync XML elements. Schulzrinne & Tschofenig Expires April 29, 2010 [Page 18] Internet-Draft LoST Sync October 2009 6. RelaxNG Location-to-Service Translation (LoST) Synchronization Protocol Schulzrinne & Tschofenig Expires April 29, 2010 [Page 19] Internet-Draft LoST Sync October 2009 Schulzrinne & Tschofenig Expires April 29, 2010 [Page 20] Internet-Draft LoST Sync October 2009 7. Security Considerations This document defines a protocol for exchange of mapping information between two entities. Hence, the operations described in this document involve mutually-trusting LoST nodes. These nodes need to authenticate each other, using mechanisms such as HTTP Digest [RFC2617], HTTP Basic [RFC2617] over TLS [RFC5246] or TLS client and server certificates. Manual configuration for the setup of the peering relationships is required and hence the choice of the security mechanisms used between the two entities is a deployment specific decision. In any case, it MUST be ensured that the two end points are authenticated and that a secure communication channel (i.e., an integrity protected exchange of data with the help of the TLS Record Layer) is setup to avoid the possibility of injecting bogus mappings. If an adversary manages to inject false mappings then this could lead to denial of service attacks. If the mapping data contains a URL that does not exist then emergency services for the indicated area are not reachable. If all mapping data contains URLs that point to a single PSAP (rather than a large number) then this PSAP is likely to experience overload conditions. If the mapping data contains a URL that points to a server controlled by the adversary itself then it might impersonate PSAPs. Schulzrinne & Tschofenig Expires April 29, 2010 [Page 21] Internet-Draft LoST Sync October 2009 8. IANA Considerations 8.1. Content-type registration for 'application/lostsync+xml' This specification requests the registration of a new MIME type according to the procedures of RFC 4288 [RFC4288] and guidelines in RFC 3023 [RFC3023]. MIME media type name: application MIME subtype name: lostsync+xml Mandatory parameters: none Optional parameters: charset Indicates the character encoding of enclosed XML. Encoding considerations: Uses XML, which can employ 8-bit characters, depending on the character encoding used. See RFC 3023 [RFC3023], Section 3.2. Security considerations: This content type is designed to carry LoST Syncronization protocol payloads. Interoperability considerations: None Published specification: RFCXXXX [NOTE TO IANA/RFC-EDITOR: Please replace XXXX with the RFC number of this specification.] Applications which use this media type: Emergency and Location-based Systems Additional information: Schulzrinne & Tschofenig Expires April 29, 2010 [Page 22] Internet-Draft LoST Sync October 2009 Magic Number: None File Extension: .lostsyncxml Macintosh file type code: 'TEXT' Personal and email address for further information: Hannes Tschofenig, Hannes.Tschofenig@nsn.com Intended usage: LIMITED USE Author: This specification is a work item of the IETF ECRIT working group, with mailing list address . Change controller: The IESG 8.2. LoST Sync Relax NG Schema Registration URI: urn:ietf:params:xml:schema:lostsync1 Registrant Contact: IETF ECRIT Working Group, Hannes Tschofenig (Hannes.Tschofenig@gmx.net). Relax NG Schema: The Relax NG schema to be registered is contained in Section 6. 8.3. LoST Synchronization Namespace Registration URI: urn:ietf:params:xml:ns:lostsync1 Registrant Contact: IETF ECRIT Working Group, Hannes Tschofenig (Hannes.Tschofenig@gmx.net). XML: Schulzrinne & Tschofenig Expires April 29, 2010 [Page 23] Internet-Draft LoST Sync October 2009 BEGIN LoST Synchronization Namespace

Namespace for LoST server synchronization

urn:ietf:params:xml:ns:lost1:sync

See RFCXXXX [NOTE TO IANA/RFC-EDITOR: Please replace XXXX with the RFC number of this specification.].

END Schulzrinne & Tschofenig Expires April 29, 2010 [Page 24] Internet-Draft LoST Sync October 2009 9. Acknowledgments Robins George, Cullen Jennings, Karl Heinz Wolf, Richard Barnes, Mayutan Arumaithurai and Andrew Newton provided helpful input. Jari Urpalainen assisted with the Relax NG schema. We would also like to thank our PROTO shepherd Roger Marshall for his help with the document. Schulzrinne & Tschofenig Expires April 29, 2010 [Page 25] Internet-Draft LoST Sync October 2009 10. References 10.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. [RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S., Leach, P., Luotonen, A., and L. Stewart, "HTTP Authentication: Basic and Digest Access Authentication", RFC 2617, June 1999. [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000. [RFC3023] Murata, M., St. Laurent, S., and D. Kohn, "XML Media Types", RFC 3023, January 2001. [RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and Registration Procedures", BCP 13, RFC 4288, December 2005. [RFC5222] Hardie, T., Newton, A., Schulzrinne, H., and H. Tschofenig, "LoST: A Location-to-Service Translation Protocol", RFC 5222, August 2008. [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, August 2008. 10.2. Informative References [RFC5582] Schulzrinne, H., "Location-to-URL Mapping Architecture and Framework", RFC 5582, September 2009. Schulzrinne & Tschofenig Expires April 29, 2010 [Page 26] Internet-Draft LoST Sync October 2009 Authors' Addresses Henning Schulzrinne Columbia University Department of Computer Science 450 Computer Science Building New York, NY 10027 US Phone: +1 212 939 7004 Email: hgs+ecrit@cs.columbia.edu URI: http://www.cs.columbia.edu Hannes Tschofenig Nokia Siemens Networks Linnoitustie 6 Espoo 02600 Finland Phone: +358 (50) 4871445 Email: Hannes.Tschofenig@gmx.net URI: http://www.tschofenig.priv.at Schulzrinne & Tschofenig Expires April 29, 2010 [Page 27]