< draft-wing-sip-e164-rrc-00.txt   draft-wing-sip-e164-rrc-01.txt >
Network Working Group D. Wing Network Working Group D. Wing
Internet-Draft Cisco Internet-Draft Cisco
Intended status: Standards Track February 5, 2008 Intended status: Standards Track February 8, 2008
Expires: August 8, 2008 Expires: August 11, 2008
SIP E.164 Return Routability Check (RRC) SIP E.164 Return Routability Check (RRC)
draft-wing-sip-e164-rrc-00 draft-wing-sip-e164-rrc-01
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
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have been or will be disclosed, and any of which he or she becomes 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. aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
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This Internet-Draft will expire on August 8, 2008. This Internet-Draft will expire on August 11, 2008.
Copyright Notice Copyright Notice
Copyright (C) The IETF Trust (2008). Copyright (C) The IETF Trust (2008).
Abstract Abstract
SIP lacks a mechanism to determine which domain can claim ownership SIP lacks a mechanism to determine which domain can claim ownership
of a certain telephone number. Due to this, it is impossible to of a certain telephone number. Due to this, it is impossible to
establish meaningful identity or to authenticate endpoints that use establish meaningful identity or to authenticate endpoints that use
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3. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.1. Verifier Operation . . . . . . . . . . . . . . . . . . . . 4 3.1. Verifier Operation . . . . . . . . . . . . . . . . . . . . 4
3.2. Authentication Service or Calling Endpoint Operation . . . 5 3.2. Authentication Service or Calling Endpoint Operation . . . 5
4. Performance Considerations . . . . . . . . . . . . . . . . . . 5 4. Performance Considerations . . . . . . . . . . . . . . . . . . 5
5. Deployment Considerations . . . . . . . . . . . . . . . . . . 5 5. Deployment Considerations . . . . . . . . . . . . . . . . . . 5
6. Security Considerations . . . . . . . . . . . . . . . . . . . 6 6. Security Considerations . . . . . . . . . . . . . . . . . . . 6
7. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 7. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
8.1. Reverse-Route Event Package . . . . . . . . . . . . . . . 9 8.1. Reverse-Route Event Package . . . . . . . . . . . . . . . 9
8.2. The "application/return-routability-nonce" Media Type . . 9 8.2. The "application/return-routability-nonce" Media Type . . 9
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 10
9.1. Normative References . . . . . . . . . . . . . . . . . . . 10 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
9.2. Informational References . . . . . . . . . . . . . . . . . 10 10.1. Normative References . . . . . . . . . . . . . . . . . . . 10
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 10 10.2. Informational References . . . . . . . . . . . . . . . . . 10
Intellectual Property and Copyright Statements . . . . . . . . . . 11 Appendix A. Changes . . . . . . . . . . . . . . . . . . . . . . . 10
A.1. Changes from -00 to -01 . . . . . . . . . . . . . . . . . 11
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 11
Intellectual Property and Copyright Statements . . . . . . . . . . 12
1. Introduction 1. Introduction
SIP [RFC3261] allows using both email-style addresses (user@domain) SIP [RFC3261] allows using both email-style addresses (user@domain)
and telephone-style addresses (1234@domain). The latter is most and telephone-style addresses (1234@domain). The latter is most
often used with E.164 [ITU.E164.1991] numbers, especially between often used with E.164 [ITU.E164.1991] numbers (designated with
different administrative domains. ";user=phone") especially between different administrative domains.
SIP's use of E.164 numbers poses several problems. This draft SIP's use of E.164 numbers poses several problems. This draft
provides a solution to one of the problems: determining if a domain provides a solution to one of the problems: determining if a domain
name rightfully 'owns' an E.164 phone number. In order to do this, a name rightfully 'owns' an E.164 phone number. In order to do this, a
new SIP request is routed towards that E.164 and, if it is received new SIP request is routed towards that E.164 and, if it is received
by the same domain, that domain is deemed to 'own' that E.164 number. by the same domain, that domain is deemed to 'own' that E.164 number.
This is termed a 'return routability check' (RRC). This is termed a 'return routability check' (RRC).
The return routability check relies on SIP routing to ascertain which The return routability check relies on SIP routing to ascertain which
domain 'owns' a certain E.164 number. domain 'owns' a certain E.164 number.
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Verifier has an additional task: it sends an out of dialog SIP Verifier has an additional task: it sends an out of dialog SIP
SUBSCRIBE request containing a random nonce to that E.164, using the SUBSCRIBE request containing a random nonce to that E.164, using the
Verifier's default SIP routing rules for routing an E.164 address. Verifier's default SIP routing rules for routing an E.164 address.
The domain that owns the E.164 will sign the nonce and send a NOTIFY The domain that owns the E.164 will sign the nonce and send a NOTIFY
request back. request back.
The steps the Verifier uses to perform this operation are: The steps the Verifier uses to perform this operation are:
1. Strip the domain name of the From: of the incoming INVITE. This 1. Strip the domain name of the From: of the incoming INVITE. This
results in a TEL URI. For example, results in a TEL URI. For example,
"sip:+14085551234@example.com" is rewritten to "sip:+14085551234@example.com;user=phone" is rewritten to
"tel:+14085551212"s "tel:+14085551212".
2. Rewrite the TEL URI to a SIP URI, following the Verifier's 2. Rewrite the TEL URI to a SIP URI, following the Verifier's
default routing rules. For example, "tel:+14085551212" is default routing rules. For example, if outgoing calls are sent
rewritten to "sip:+14085551212@example.net", the service provider to the service provider example.net, then "tel:+14085551212" is
used by the verifying domain). rewritten to "sip:+14085551212@example.net;user=phone".
3. Generate a random nonce. 3. Generate a random nonce.
4. Using the SIP URI constructed in step (2), construct a SIP 4. Using the SIP URI constructed in step (2), construct a SIP
SUBSCRIBE message with Request-URI and To headers that use that SUBSCRIBE message with Request-URI and To headers that use that
SIP URI, and an "Expires" header of 0. The SUBSCRIBE contains SIP URI, and an "Expires" header of 0. The SUBSCRIBE contains
the random nonce in its body as Content-Type application/ the random nonce in its body as Content-Type application/
return-routability-nonce. return-routability-nonce.
5. Send the SUBSCRIBE message. This will cause the calling party to 5. Send the SUBSCRIBE message. This will cause the calling party to
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Macintosh File Type Code(s): none. Macintosh File Type Code(s): none.
Person & email address to contact for further information: Dan Wing Person & email address to contact for further information: Dan Wing
<dwing@cisco.com> <dwing@cisco.com>
Intended Usage: COMMON Intended Usage: COMMON
Author/Change Controller: Dan Wing <dwing@cisco.com> Author/Change Controller: Dan Wing <dwing@cisco.com>
9. References 9. Acknowledgements
9.1. Normative References Thanks to Paul Kyzivat and Hannes Tschofenig for their review and
comments on this document. Thanks to Joel Halpern for pointing out
the missing ";user=phone" parameter.
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4474] Peterson, J. and C. Jennings, "Enhancements for [RFC4474] Peterson, J. and C. Jennings, "Enhancements for
Authenticated Identity Management in the Session Authenticated Identity Management in the Session
Initiation Protocol (SIP)", RFC 4474, August 2006. Initiation Protocol (SIP)", RFC 4474, August 2006.
[RFC3265] Roach, A., "Session Initiation Protocol (SIP)-Specific [RFC3265] Roach, A., "Session Initiation Protocol (SIP)-Specific
Event Notification", RFC 3265, June 2002. Event Notification", RFC 3265, June 2002.
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E. A., Peterson, J., Sparks, R., Handley, M., and E.
Schooler, "SIP: Session Initiation Protocol", RFC 3261, Schooler, "SIP: Session Initiation Protocol", RFC 3261,
June 2002. June 2002.
9.2. Informational References 10.2. Informational References
[ITU.E164.1991] [ITU.E164.1991]
International Telecommunications Union, "The International International Telecommunications Union, "The International
Public Telecommunication Numbering Plan", ITU- Public Telecommunication Numbering Plan", ITU-
T Recommendation E.164, 1991. T Recommendation E.164, 1991.
Appendix A. Changes
[[RFC Editor: Please remove this section prior to publication.]]
A.1. Changes from -00 to -01
o Added ";user=phone" to identify E.164 number.
Author's Address Author's Address
Dan Wing Dan Wing
Cisco Systems, Inc. Cisco Systems, Inc.
170 West Tasman Drive 170 West Tasman Drive
San Jose, CA 95134 San Jose, CA 95134
USA USA
Email: dwing@cisco.com Email: dwing@cisco.com
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