GEOPRIV M. Thomson Internet-Draft J. Winterbottom Intended status: Standards Track Andrew Expires: January 4, 2009 July 3, 2008 A BEEP Binding for the HELD Protocol draft-thomson-geopriv-held-beep-02 Status of This Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of 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 January 4, 2009. Abstract A BEEP binding is described for HELD. This binding is more suitable than the basic HTTP binding in scenarios where multiple messages are sent between the same two parties. Thomson & Winterbottom Expires January 4, 2009 [Page 1] Internet-Draft HELD over BEEP July 2008 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2. The HELD BEEP Profile . . . . . . . . . . . . . . . . . . . . 3 2.1. Channel Initialization . . . . . . . . . . . . . . . . . . 4 2.2. Message Exchange Pattern . . . . . . . . . . . . . . . . . 4 2.3. Error Handling . . . . . . . . . . . . . . . . . . . . . . 5 2.4. Asynchronous Message Exchange . . . . . . . . . . . . . . 5 3. The "held+beep:" URI . . . . . . . . . . . . . . . . . . . . . 5 3.1. Location By-Reference and the BEEP Binding . . . . . . . . 6 4. LIS Discovery and Authentication for BEEP . . . . . . . . . . 6 5. Security Considerations . . . . . . . . . . . . . . . . . . . 7 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 6.1. BEEP Profile Registration . . . . . . . . . . . . . . . . 7 6.2. URN sun-namespace registration for 'urn:ietf:params:xml:ns:geopriv:held:beep' . . . . . . . . 7 6.3. Registration of the "held+beep:" URI Scheme . . . . . . . 8 6.4. Registration of a LIS Application Protocol Tag for HELD over BEEP . . . . . . . . . . . . . . . . . . . . . . 9 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 7.1. Normative References . . . . . . . . . . . . . . . . . . . 9 7.2. Informative References . . . . . . . . . . . . . . . . . . 11 Thomson & Winterbottom Expires January 4, 2009 [Page 2] Internet-Draft HELD over BEEP July 2008 1. Introduction The HTTP binding for HELD [I-D.ietf-geopriv-http-location-delivery] provides a basis for the protocol, which does not encumber implementations with a complex protocol stack. However, some applications require that a requester make multiple requests in parallel to a Location Information Server (LIS). [I-D.winterbottom-geopriv-lis2lis-req] and [I-D.winterbottom-geopriv-held-lis2lis-bcp] describe use cases and an application of HELD where HTTP is suboptimal. The HTTP binding is not suitable in volume scenarios because HTTP suffers from head-of-queue blocking. This prevents multiple requests from being processed in parallel. In order to achieve higher throughput, the requester must establish multiple TCP connections in parallel. This causes HTTP to be unsuitable for applications where multiple parallel requests are expected by increasing the overheads. BEEP [RFC3080] provides a framing scheme that allows for parallel requests. BEEP uses MIME [RFC2045] for its messages, which means that no significant modifications are required to carry HELD messages. This document describes a BEEP profile for HELD. 1.1. 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 [RFC2119]. 2. The HELD BEEP Profile The BEEP profile for HELD is identified as: urn:ietf:params:xml:ns:geopriv:held:beep This identifier is used in the BEEP "profile" element during channel creation. The HELD channel is a simple continuous channel that does not require any state information. Requests and their respective responses are always in the request-response form ("MSG"/"RPY"). Thomson & Winterbottom Expires January 4, 2009 [Page 3] Internet-Draft HELD over BEEP July 2008 2.1. Channel Initialization The HELD profile is started with a single "profile" request. No additional parameters are required. When initiating a channel the "profile" element MUST be empty, as shown in the example below. The "serverName" attribute on the "start" message serves the same purpose as the HTTP [RFC2616] "Host" header in informing the server of the name it is known by. Similarly, the response to channel initialization MUST be empty. 2.2. Message Exchange Pattern The BEEP binding for HELD requires only the "MSG"/"RPY" message exchange. Each "MSG" frame contains a request, which may be either a "locationRequest", "createContext" or "updateContext". Each "RPY" frame includes a response, either a PIDF-LO (i.e. "presence"), or a "contextResponse". The following exchange demonstrates how a simple HELD location request and response are encapsulated. The "C:" and "S:" prefixes on lines are used following the convention in [RFC3080]. C: MSG 1 7 . 544 125 C: Content-Type: application/held+xml C: C: C: C: END S: RPY 1 7 . 1902 695 S: Content-Type: application/held+xml S: S: S: S: S: S: END Thomson & Winterbottom Expires January 4, 2009 [Page 4] Internet-Draft HELD over BEEP July 2008 2.3. Error Handling The HELD BEEP binding does not use the BEEP "ERR" message to indicate errors at the HELD protocol level. Errors in handling HELD Requests are indicated to the requester in a "RPY" message. Errors in the BEEP message that are unrelated to the HELD protocol, such as MIME formatting problems, are indicated using the BEEP "ERR" message. This "ERR" message MAY either be empty or it could include textual feedback. 2.4. Asynchronous Message Exchange A HELD request can take varying amounts of time to process. The "responseTime" attribute in HELD is used to indicate an upper bound on this time. BEEP channels are serial in nature and BEEP mandates that the serving peer process requests in order. With these constraints, in order to acheive any substantial throughput, multiple BEEP channels would be necessary. This approach does not scale well as response times increase. It is RECOMMENDED that for HELD on BEEP that both peers use asynchronous BEEP [I-D.thomson-beep-async]. Asynchronous BEEP enables the use of a single channel for multiple requests without constraints on how requests are processed or on the order of responses. Asynchronous BEEP greatly increases the potential throughput of a channel, particularly for profiles like HELD that could have widely varying response times. Without asynchronous BEEP, multiple channels MAY be used to increase throughput. 3. The "held+beep:" URI A new URI form is defined to describe a BEEP binding instance. The "held+beep:" URI includes server, port and an identifier that can be used to construct a location reference. The "held+beep:" URI is constructed as shown in Figure 1 using ABNF [RFC4234] and the definitions for URI components from [RFC3986]. ; all undefined items are specified in RFC 3986 HB-URI = "held+beep" ":" hier-part [ "?" query ] hier-part = "//" authority path-abempty / path-absolute / path-rootless / path-empty authority = host ":" port Figure 1: The "held+beep:" URI There is no well-known port for this binding; therefore, the port component of the URI MUST be included. Thomson & Winterbottom Expires January 4, 2009 [Page 5] Internet-Draft HELD over BEEP July 2008 3.1. Location By-Reference and the BEEP Binding The "path" and "query" components of the "held+beep:" URI are used in a similar fashion to the analagous components in HTTP/1.1 [RFC2616]. These components can be conveyed for each request by including them in the MIME headers for each request. The "Request-URI" header includes an absolute path and optional query components. The header is shown in Figure 2, using ABNF [RFC4234]. Request-URI-Header = "Request-URI" ":" Request-URI ; Request-URI from RFC 2616 Figure 2: The Request-URI Header This header is modelled on the "Request-URI" field in HTTP/1.1 [RFC2616] and it follows the same rules. See Section 5.1.2 of [RFC2616] for details on how to use this header. A value of "*" implies that no location URI is being used, this value should be assumed when the header is omitted. A value of "*" is assumed if a "held+beep:" URI does not contain path or query elements. 4. LIS Discovery and Authentication for BEEP This profile is most suited to situations where a client and LIS exchange a large number of requests over a prolonged period. It is anticipated that the client and LIS are known to each other. Based on this assumption, it is reasonable for the LIS and its clients to have pre-existing configuration that makes discovery unnecessary. In addition, authentication details and methods can be pre-configured on both nodes. This section outlines how discovery can be performed for a LIS that supports the BEEP binding. Regardless of the method used to determine the address of the LIS, a client MUST authenticate the LIS. This prevents any LIS spoofing attacks that could be used to acquire information about the client (and in turn, their clients). For persistent connections, it is RECOMMENDED that the LIS also authenticate clients. Some authorization decision is likely to be necessary in order for a client to initiate a large volume of requests, which could represent significant load on a LIS. This document does not mandate any specific authentication method; however, since TLS MUST be implemented, the mandatory methods in [RFC4346] are assumed to be present. Alternative authentication methods can be negotiated between the LIS and its clients. Thomson & Winterbottom Expires January 4, 2009 [Page 6] Internet-Draft HELD over BEEP July 2008 5. Security Considerations TLS [RFC4346] SHOULD be used for HELD over BEEP unless confidentiality, message integrity and authentication are assured through other means (e.g. dedicated media). It is RECOMMENDED that BEEP peers establish a TLS connection immediately, rather than relying on the TLS tuning profile in BEEP. 6. IANA Considerations 6.1. BEEP Profile Registration This section outlines the HELD BEEP binding in the form described in [RFC3080]. Profile Identification: urn:ietf:params:xml:ns:geopriv:held:beep Messages exchanged during Channel Creation: none Messages starting one-to-one exchanges: HELD request messages from [I-D.ietf-geopriv-http-location-delivery] and extension documents. Messages in positive replies: HELD request messages from [I-D.ietf-geopriv-http-location-delivery] and extension documents. Messages in negative replies: The HELD "error" message Messages in one-to-many exchanges: none Message Syntax: c.f., HELD [I-D.ietf-geopriv-http-location-delivery] Message Semantics: c.f., HELD [I-D.ietf-geopriv-http-location-delivery] Contact Information: c.f., the "Author's Address" section of this document 6.2. URN sun-namespace registration for 'urn:ietf:params:xml:ns:geopriv:held:beep' This section registers a new XML namespace, "urn:ietf:params:xml:ns:geopriv:held:beep", as per the guidelines in [RFC3688]. URI: urn:ietf:params:xml:ns:geopriv:held:beep Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). Thomson & Winterbottom Expires January 4, 2009 [Page 7] Internet-Draft HELD over BEEP July 2008 XML: BEGIN HELD BEEP Binding

Namespace for HELD BEEP Binding Profile

urn:ietf:params:xml:ns:geopriv:held:beep

[[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX with the RFC number for this specification.]]

See RFCXXXX.

END 6.3. Registration of the "held+beep:" URI Scheme This section registers the "held+beep:" URI scheme with the IANA, following the guidelines in [RFC4395]. URI scheme name: held+beep Status: permanent URI scheme syntax: See Figure 1 in Section 3. URI scheme semantics: A held+beep URI defines a means of accessing a LIS, or it can be used to convey a location URI, see Section 3. Encoding considerations: A held+beep URI is not designed to include internationalized text, it is created and consumed by automated processes only. Internationalized domain names [RFC3490] can be included in the authority part of the URI, but path components are not intended for user entry. Applications/protocols that use this URI scheme name: The held+beep URI is used by Location Information Servers (LIS) as a means of describing a service, or as a location reference. Interoperability considerations: No specific considerations. Thomson & Winterbottom Expires January 4, 2009 [Page 8] Internet-Draft HELD over BEEP July 2008 Security considerations: No specific considerations. Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). References: RFCXXXX (this document), RFCXXXX (HELD) 6.4. Registration of a LIS Application Protocol Tag for HELD over BEEP This section registers a new S-NAPTR Application Protocol tag for the BEEP binding of the HELD [I-D.ietf-geopriv-http-location-delivery] protocol, as mandated by [RFC3958]. Application Service Tag: HELD+BEEP Intended Usage: Identifies the HELD protocol over BEEP Applicable Service Tag(s): LIS Terminal NAPTR Record Type(s): S Defining Publication: RFCXXXX Related Publications: HELD [I-D.ietf-geopriv-http-location-delivery] Contact Information: The authors of this document Author/Change Controller: The IESG 7. References 7.1. Normative References [RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996. [RFC3080] Rose, M., "The Blocks Extensible Exchange Protocol Core", RFC 3080, March 2001. [RFC3958] Daigle, L. and A. Thomson & Winterbottom Expires January 4, 2009 [Page 9] Internet-Draft HELD over BEEP July 2008 Newton, "Domain-Based Application Service Location Using SRV RRs and the Dynamic Delegation Discovery Service (DDDS)", RFC 3958, January 2005. [RFC4346] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.1", RFC 4346, April 2006. [I-D.ietf-geopriv-http-location-delivery] Barnes, M., Winterbottom, J., Thomson, M., and B. Stark, "HTTP Enabled Location Delivery (HELD)", draft-ietf- geopriv-http-location- delivery-07 (work in progress), April 2008. [RFC4234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 4234, October 2005. [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, January 2005. [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. [RFC2119] Bradner, S., "Key words for use in RFCs to Thomson & Winterbottom Expires January 4, 2009 [Page 10] Internet-Draft HELD over BEEP July 2008 Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 7.2. Informative References [RFC3490] Faltstrom, P., Hoffman, P., and A. Costello, "Internationalizing Domain Names in Applications (IDNA)", RFC 3490, March 2003. [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, January 2004. [RFC4395] Hansen, T., Hardie, T., and L. Masinter, "Guidelines and Registration Procedures for New URI Schemes", BCP 115, RFC 4395, February 2006. [I-D.thomson-beep-async] Thomson, M., "Asynchronous Channels for the Blocks Extensible Exchange Protocol (BEEP)", draft- thomson-beep-async-00 (work in progress), May 2008. [I-D.winterbottom-geopriv-lis2lis-req] Winterbottom, J. and S. Norreys, "LIS to LIS Protocol Requirements", draft-winterbottom- geopriv-lis2lis-req-01 (work in progress), November 2007. [I-D.winterbottom-geopriv-held-lis2lis-bcp] Winterbottom, J. and M. Thomson, "Using HELD for Inter-LIS Communication", draft- winterbottom-geopriv- held-lis2lis-bcp-00 Thomson & Winterbottom Expires January 4, 2009 [Page 11] Internet-Draft HELD over BEEP July 2008 (work in progress), November 2007. Authors' Addresses Martin Thomson Andrew PO Box U40 Wollongong University Campus, NSW 2500 AU Phone: +61 2 4221 2915 EMail: martin.thomson@andrew.com URI: http://www.andrew.com/ James Winterbottom Andrew PO Box U40 Wollongong University Campus, NSW 2500 AU Phone: +61 2 4221 2938 EMail: james.winterbottom@andrew.com URI: http://www.andrew.com/ Thomson & Winterbottom Expires January 4, 2009 [Page 12] Internet-Draft HELD over BEEP July 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Intellectual Property The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Thomson & Winterbottom Expires January 4, 2009 [Page 13]