Recommended Relationships between Different Types of Identifiers draft-schulzrinne-sipping-id-relationships-00 Henning Schulzrinne (Columbia U.) Eunsoo Shim (Panasonic) eunsoo@research.panasonic.com hgs@cs.columbia.edu August 2005 IETF63 - SIPPING

Overview No public directory deployed or likely Often, only partial information available e.g., auto-addressbook in mail user agents Set of user@domain-style identifiers SMTP (RFC 2821) SIP XMPP (also NAI: RADIUS and DIAMETER) August 2005 IETF63 - SIPPING

Motivation User experience: Users think of addresses like alice@example.com, not sip:alice@example.com or mailto:alice@example.com Authentication: single sign-on identifier also allows easy SIP account creation create sip:alice@example.com; password mailed to alice@example.com Spam prevention: use earlier email exchange as white list for SIP “I have sent email to bob@example.com, so I’m accepting IM from sip:bob@example.com” Problem: No clear guidance on identifier creation and relationships August 2005 IETF63 - SIPPING

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 August 2005 IETF63 - SIPPING

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? August 2005 IETF63 - SIPPING