Extended REFER

draft-olson-sipping-refer-extensions-01

draft-mahy-sip-remote-cc-01François Audet mailto:audet@nortelnetworks.com

Orit Levin mailto:oritl@microsoft.com

Rohan Mahy mailto:rohan@cisco.com

draft-olson-sipping-refer-extension-01

• Replacing Refer-To URI Syntax with a MIME Body

• Suppressing the REFER Implicit Subscription with norefersub

• Binding Arbitrary Event Packages with REFER

• Applying REFER to SIP Response Codes• Adding call-id and tag Parameters to

Refer-To Header

Replacing Refer-To URI Syntax with a MIME Body

• Requirements: Rough Consensus– REFER was intended to be a general mechanism– REFER needs to be able to specify both generalized

operation and generalized target

• Mechanism: Still needs polishing– “Extended-refer” Option Tag – Refer-To: cid:cn35t8jf02@example.com – cid can be placed in the body and be expressed in

XML format

Suppressing Implicit Subscription

• Status: Consensus

• Mechanism: Rough Consensus– Use GRUU for forking prevention

• no extension required

–“Norefersub”• Require: Option Tag

– or Refer-To header parameter?

Binding Arbitrary Event Packages with REFER

• Functionality can be achieved by explicit subscription to any event package

• Reusing “Allow-Events” and “Event” headers in REFER

REFERring SIP Responses with Codes

• Requirements: Debatable

• Mechanism– “refer-response” Option Tag

• Not for provisional responses

Adding “callid” and “tag” Parameters to Refer-To Header

• Requirements: TBD

• Mechanism: TBD– call-id=123;remote-tag=aaa;local-tag=bbb

draft-mahy-sip-remote-cc-01

• “Manipulation of conversations and session-oriented dialogs by a UA that is not directly involved in any of the relevant conversations, dialogs or sessions”

• “Controller” is a regular UA (not 3rd party call control)

draft-mahy-sip-remotecc-01

• Loosely coupled UAs presenting a coordinated user experience:– SIP Phone, Internet appliances– General purpose computer, PDA

• Can be bidirectional (e.g., phone ↔ PC)

• May use dialog package, norefersub• Builds on draft-olson-sipping-refer-extensions-01

Remote Call Control Operations

• Make Call• Answer Call• Clear Connection• Deflect Call• Single Step Transfer• Hold Call• Retrieve Call• Conference Call

• Single Step Conference• Set Do Not Disturb• Set Forwarding• Alternate Call• Consultation Call

• Only “Typical use cases”

Implementing operations

• Use Refer-To-URI only helps for the simpler operations– Refer-to: sip:....;method=INVITE;response=200– ;call-id=123;remote-tag=aaa;local-tag=bbb– urn:ietf:params:sip:remotecc:operation?

• Some operations require REFER Body – Too complex escaping in REFER– More abstract– UA controller doesn’t want to know too much about

remote controlled UA

REFER REFER sip:reg2@10.1.1.3 SIP/2.0 Via: SIP/2.0/TCP issuer.example.com.com;branch=z9hG4bK-a-1 To: "Alice's phone" <sip:reg2@10.1.1.3> From: "Alice's PC or PDA" <sip:alice1@10.1.1.2>;tag=abc Call-ID: 123@issuer.example.com CSeq: 2 REFER Max-Forwards: 70 Contact: sip:alice1@10.1.1.2 Accept: application/dialog-info+xml Require: extended-refer Refer-To: <cid:1239103912039@issuer.example.com>;

call-id=123;remote-tag=aaa;local-tag=bbb Content-Type: application/remotecc Content-Id: <1239103912039@issuer.example.com> Content-Length: ...

---------------------------- | Remote Call Control Body | ----------------------------

To Do (draft-mahy-sip-remote-cc)

• Can we use more generic operations?– Don’t want to get into “well-defined features

with names”– Should address in next revision

• Define XML bodies for operations