Internet DRAFT - draft-kaplan-dnsext-enum-sip-source-ref-opt-code

draft-kaplan-dnsext-enum-sip-source-ref-opt-code




Network Working Group                                         H. Kaplan 
Internet Draft                                              Acme Packet 
Intended status: Informational                                R. Walter 
Expires: April 24, 2012                                       NetNumber 
                                                              P. Gorman 
                                                          Sprint Nextel 
                                                           M. Maharishi 
                                                                    TNS 
                                                       October 24, 2011 
    
    
          EDNS Option Code for SIP and PSTN Source Reference Info 
            draft-kaplan-dnsext-enum-sip-source-ref-opt-code-03 
    
    
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Abstract
    
   This document requests an IANA allocation for an EDNS0 Option-Code, 
   per [RFC2671], for a UTF-8 encoded string field containing a URI for 
   private use.  The intended use of this field is for providing SIP 
   and PSTN-type source information for ENUM-resolution DNS queries, in 
   private DNS server environments such as Private ENUM. 

    
Table of Contents
    
   1. Introduction..................................................2 
   2. Terminology...................................................3 
   3. Applicability.................................................3 
   4. OPTION-DATA Format............................................3 
   5. Security Considerations.......................................3 
   6. IANA Considerations...........................................4 
   7. Acknowledgments...............................................4 
   8. References....................................................4 
      8.1. Normative References.....................................4 
      8.2. Informative References...................................4 
   Authors' Addresses................................................4 
    
    
1. Introduction 
    
   In many VoIP domains, private DNS servers are used to provide ENUM 
   resolution for SIP request routing purposes.  Devices in such 
   domains, such as SIP Proxies and PSTN Gateways, which are the DNS 
   clients set to use the private DNS servers for ENUM resolution, need 
   to provide the server(s) with some additional private meta-data 
   concerning the source of the SIP request that triggered the DNS 
   query, which may aid the server(s) in providing an answer.  The 
   additional data is in the form of a URI-formatted UTF-8 string, 
   which needs to be provided in the DNS query request.  The Extension 
   Mechanism for DNS (EDNS) defined in [RFC2671] provides a suitable 
   means by which to encode such a string into the DNS request, using 
   the OPT RR and a new EDNS0 Option-Code indicating this field use.   
    
   This document requests IANA for assignment of such an Option-Code, 
   for providing SIP and PSTN-type source reference information in DNS 
   requests used for ENUM, in private, controlled environments only.  
   This is neither applicable to, nor appropriate for, the general 
   public Internet DNS; the only reason this document exists is to 

 
 
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   obtain a reserved option code number, for interoperability among 
   vendors within private, restricted environments. 
    
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.  The 
   terminology in this document conforms to RFC 2828, "Internet 
   Security Glossary". 
    
   Private DNS server: a DNS server which does not use the IANA-base 
   tree, nor the "e164.arpa" suffix, and is deployed for specific name 
   resolution purposes in a controlled, restricted environment. 
    
3. Applicability 
    
   This draft requests a new Option code value based on [EDNS0].  
    
4. OPTION-DATA Format 
    
   The format of the OPTION-DATA contents is a UTF-8 [RFC2279] text 
   string, with no character termination (the OPTION-LENGTH field 
   identifies the length). 
    
   For the private use defined for this option code, the contents of 
   the UTF-8 string are a URI, typically a SIP or TEL URI, including 
   the "sip:" or "tel:" schemes.  Non-UTF-8 characters, or characters 
   not allowed in the ABNF rules for a SIP-URI or TEL-URI format per 
   [RFC3261] or [RFC3966] MUST be escaped per those formats. 
    
   The usage and source of the URI content is outside the scope of this 
   document, and are documented in [draft-enum-sip-routing]. 
    
   The query option is of a multi-hop, transitive nature.  As such, 
   this mechanism will only work in restricted DNS server use cases 
   where all the DNS servers (and intermediate caches) are known to 
   support the extension.  The primary use-case for this is in Private 
   ENUM deployments. 
    
5. Security Considerations 
    
   There are privacy concerns with regard to passing SIP/PSTN source 
   reference information in a DNS query.  The intent of this option is 
   for a purely private use, in a controlled environment.  Clients MUST 
   NOT use this option mechanism if they do not know the DNS query will 
   only be processed by private DNS servers in a controlled 
   environment, for example through explicit configuration that such is 
   the case. 
 
 
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6.   IANA Considerations 
    
   This document requests that IANA register in the "Domain Name System 
   (DNS) Parameters" registry at http://www.iana.org/assignments/dns-
   parameters in sub-registry "DNS EDNS0 Options", a new option named 
   "SIP/PSTN Source Reference Info". 
    
7.   Acknowledgments 
    
   Thanks to Tom Creighton (Comcast), James Yu (Neustar), Nick Russell 
   (Vodafone), Colin Pons (KPN), and Raja Gopal (Nominum) for their 
   input and support.  Funding for the RFC Editor function is provided 
   by the IETF Administrative Support Activity (IASA). 
    
8.   References 
    
8.1. Normative References 
 
   [RFC2279]  Yergeau, F., "UTF-8, a transformation format of ISO 
   10646", RFC 2279, January 1998. 
    
   [RFC2671]  Vixie, P., "Extension Mechanisms for DNS (EDNS0)", RFC 
   2671, August 1999. 
    
   [RFC3261]  Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, 
   A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: 
   Session Initiation Protocol", RFC 3261, June 2002. 
     
   [RFC3966] Schulzrinne, H., "The tel URI for Telephone Numbers", RFC 
   3966, December 2004. 
    
8.2. Informative References 
 
   [draft-enum-sip-routing] Kaplan, H., Pons, C., Gorman, P., "Routing 
   SIP Requests with ENUM", draft-kaplan-enum-sip-routing-04, October 
   24, 2011. 
 
Authors' Addresses
    
   Hadriel Kaplan
   Acme Packet
   100 Crosby Dr.
   Bedford, MA 01730
   USA
   Email: hkaplan@acmepacket.com
    
   Robert H. Walter
   NetNumber, Inc.
 
 
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   650 Suffolk Street, Suite 307
   Lowell, MA 01854
   USA
   Email: rwalter@netnumber.com
    
   Pierce Gorman
   Sprint Nextel Corporation
   6220 Sprint Parkway
   MS: KSOPHD0504 - 5D208
   Overland Park, KS 66251
   Email: pierce.gorman@sprint.com
    
   Manjul Maharishi
   TNS Inc.
   1939 Roland Clarke Place
   Reston, VA 20191
   USA
   Email: mmaharishi@tnsi.com































 
 
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