The LoST-Validation S-NAPTR Application Service Tag
draft-gellens-lost-validation-03

Network Working Group                                         R. Gellens
Internet-Draft                                Core Technology Consulting
Intended status: Informational                                  B. Rosen
Expires: August 2, 2020                                 January 30, 2020

          The LoST-Validation S-NAPTR Application Service Tag
                    draft-gellens-lost-validation-03

Abstract

   This document adds LoST-Validation to the S-NAPTR Application Service
   Tag IANA registry.

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Table of Contents

   1.  Document Scope  . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  The LoST-Validation Application Service Tag . . . . . . . . .   3
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
     5.1.  S-NAPTR Registration  . . . . . . . . . . . . . . . . . .   4
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   4
   7.  Changes from Previous Versions  . . . . . . . . . . . . . . .   4
     7.1.  Changes from -00 to -01 . . . . . . . . . . . . . . . . .   4
     7.2.  Changes from -01 to -02 . . . . . . . . . . . . . . . . .   5
     7.3.  Changes from -02 to -03 . . . . . . . . . . . . . . . . .   5
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     8.2.  Informative references  . . . . . . . . . . . . . . . . .   5
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   5

1.  Document Scope

   This document only adds a new Service Tag.

2.  Introduction

   The Location-to-Service Translation Protocol, LoST [RFC5222] defines
   a mapping service with the additional ability to request that a civic
   address be validated.  The National Emergency Number Association
   (NENA) has defined an architecture (known as "i3" [NENA-i3]) which
   defines the mapping and routing functions as two distinct roles,
   defined as an Emergency Call Routing Function (ECRF) and a Location
   Verification Function (LVF).  NENA i3 requires that the mapping
   (ECRF) and validation (LVF) functions be separable, so that an entity
   responsible for a LoST server cluster can decide to provide mapping
   and validation services using consolidated or separate server
   clusters (i.e., using the same or separate boxes).  The rationale is
   that the mapping service is used in real-time during emergency call
   routing, while the validation service is used in advance, typically
   when data is provisioned, and therefore the mapping service has much
   higher availability and response time requirements than the
   validation service.  An organization might choose to deploy these
   services using different server clusters to make it easier to provide
   higher levels of service for the mapping function while shielding it
   from the potentially bursty load of validation, while another
   organization might choose to use the same sets of servers for both,
   configured and deployed to offer the high service level demanded of
   the mapping service.

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   In order to permit this separability, any entity querying a LoST
   server needs to be able to resolve an Application Unique String (AUS)
   into a URL for a server that offers the required service (mapping or
   validation).  This separability needs to be maintained throughout the
   LoST tree structure, from forest guide to leaf node.  Because LoST
   referrals return an AUS rather than a URL, different Service Tags are
   needed for the different services.  This document adds 'LoST-
   Validation' to the S-NAPTR Application Service Tag registry created
   by [RFC3958].  The 'LoST-Validation' tag serves as a counterpart to
   the 'LoST' tag added by [RFC4848]: The 'LoST' tag identifies servers
   able to perform the core mapping function, while 'LoST-Validation'
   identifies servers explicitly willing to perform the validation
   function.

   Because some servers might be configured to provide both mapping and
   validation functions, a server identified using the 'LoST' service
   tag might also perform the validation function (and resolving the two
   tags might result in the same URL).  Because the two functions might
   be separate, clients seeking a LoST server for location validation
   should first try U-NAPTR resolution using the 'Lost-Validation'
   service tag, and may fallback to the 'LoST' service tag if the 'Lost-
   Validation' service tag cannot be resolved to a usable LoST server.

3.  The LoST-Validation Application Service Tag

   LoST [RFC4848] specifies that LoST servers are located by resolving
   an application Unique String (AUS) using U-NAPTR/DDDS (URI-Enabled
   NAPTR/Dynamic Delegation Discovery Service) [RFC4848], and defines
   the 'LoST' Application service tag.  In order to permit separability
   of the mapping and validation services performed using LoST, this
   document defines the 'LoST-Validation' service tag.  NAPTR records
   for LoST servers available for location validation contain the 'LoST-
   Validation' service tag.  An entity needing to perform location
   validation using LoST performs the discovery procedure as described
   in [RFC4848], except that the 'LoST-Validation' service tag is used
   in preference to the 'LoST' service tag.  For both service tags, the
   HTTP and HTTPS URL schemes are used.  In the absense of any NAPTR
   records containing the 'LoST-Validation' service tag, the 'LoST'
   service tag is used.  Fallback to the 'LoST' service tag may follow
   if the 'Lost-Validation' service tag fails to result in a usable LoST
   server.  Using the 'LoST-Validation' service tag might result in the
   same URL as the 'LoST' service tag, or it may result in a different
   URL.  The URLs might result in the same physical servers being
   contacted, or different servers.

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4.  Security Considerations

   The security considerations described in [RFC3958] and [RFC4848]
   apply here.  No additional security aspects are foreseen by the
   addition of an extra tag.  Separation of services might be desired,
   for example, to be able to allocate different levels of resources
   (such as server capacity, attack mitigation, bandwidth, etc.) to the
   mapping and validation services, in which case separate tags are
   needed to allow LoST clients (which may include other LoST servers)
   to identify the correct server cluster.

5.  IANA Considerations

   IANA is requested to add 'LoST-Validation' to the S-NAPTR Application
   Service Tag registry created by [RFC3958]  This tag serves as a
   counterpart to the 'LoST' tag added by [RFC5222].

   (Note that IANA and [RFC3958] call this registry "S-NAPTR Application
   Service Tags" while [RFC5222] calls it "U-NAPTR application service
   tag".)

5.1.  S-NAPTR Registration

   This document registers an S-NAPTR application service tag:

      Application Service Tag: LoST-Validation

      Defining Publication: This document.

6.  Acknowledgements

   Many thanks to Ted Hardie for his helpful review and suggestions.

7.  Changes from Previous Versions

7.1.  Changes from -00 to -01

   o  Fixed incorrect tag in Section 5

   o  Clarified background and explanation in Section 2

   o  Clarified text in Section 3

   o  Expanded text in Section 4

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7.2.  Changes from -01 to -02

   o  Fixed bug in .xml file

7.3.  Changes from -02 to -03

   o  Reworded fallback text in Section 2

8.  References

8.1.  Normative References

   [RFC3958]  Daigle, L. and A. Newton, "Domain-Based Application
              Service Location Using SRV RRs and the Dynamic Delegation
              Discovery Service (DDDS)", RFC 3958, DOI 10.17487/RFC3958,
              January 2005, <https://www.rfc-editor.org/info/rfc3958>.

   [RFC4848]  Daigle, L., "Domain-Based Application Service Location
              Using URIs and the Dynamic Delegation Discovery Service
              (DDDS)", RFC 4848, DOI 10.17487/RFC4848, April 2007,
              <https://www.rfc-editor.org/info/rfc4848>.

   [RFC5222]  Hardie, T., Newton, A., Schulzrinne, H., and H.
              Tschofenig, "LoST: A Location-to-Service Translation
              Protocol", RFC 5222, DOI 10.17487/RFC5222, August 2008,
              <https://www.rfc-editor.org/info/rfc5222>.

8.2.  Informative references

   [NENA-i3]  National Emergency Number Association (NENA)
              Interconnection and Security Committee, i3 Architecture
              Working Group, , "Detailed Functional and Interface
              Standards for the NENA i3 Solution", 2016,
              <https://www.nena.org/page/i3_Stage3>.

Authors' Addresses

   Randall Gellens
   Core Technology Consulting
   US

   Email: rg+ietf@coretechnologyconsulting.com
   URI:   http://www.coretechnologyconsulting.com

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   Brian Rosen
   470 Conrad Dr
   Mars, PA   16046
   US

   Email: br@brianrosen.net

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