Recommended Relationships between Different Types of Identifiers draft-schulzrinne-sipping-id-relationships-00

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Recommended Relationships between Different Types
of Identifiersdraft-schulzrinne-sipping-id-relati
onships-00

• Henning Schulzrinne (Columbia U.)
• Eunsoo Shim (Panasonic)
• eunsoo_at_research.panasonic.com
• hgs_at_cs.columbia.edu

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Overview

• No public directory deployed or likely
• Often, only partial information available
• e.g., auto-addressbook in mail user agents
• Set of user_at_domain-style identifiers
• SMTP (RFC 2821)
• SIP
• XMPP
• (also NAI RADIUS and DIAMETER)

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Motivation

• User experience Users think of addresses like
  alice_at_example.com, not sipalice_at_example.com or
  mailtoalice_at_example.com
• Authentication single sign-on identifier
• also allows easy SIP account creation
• create sipalice_at_example.com password mailed to
  alice_at_example.com
• Spam prevention use earlier email exchange as
  white list for SIP
• I have sent email to bob_at_example.com, so Im
  accepting IM from sipbob_at_example.com
• Problem No clear guidance on identifier creation
  and relationships

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Core recommendations

• User MAY choose same user name across URIs within
  same domain
• or stronger Provider SHOULD assign same user
  part across URI schemes
• Providers SHOULD NOT assign the same user id in
  different URI schemes to different people
• SIP URIs SHOULD have a working email equivalent
• motivation less clear (not necessary for
  voicemail)
• useful for initial sign-up in some scenarios

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Open issues

• Mapping of tel URIs to email and SIP URIs
  primarily issue of separators
• ignore all separators (all equivalent) OR
• specific recommendation of usage
• Is this useful enough as a BCP or Informational?