1© 1999, Cisco Systems, Inc.

Course NumberPresentation_ID

Peer-to-Peer 3rd party Peer-to-Peer 3rd party call controlcall control

Rohan Mahy—Cisco SystemsRohan Mahy—Cisco Systems

rohan@cisco.comrohan@cisco.com

2Presentation_ID © 1999, Cisco Systems, Inc.

Peer to peer 3pcc — Problem SetPeer to peer 3pcc — Problem Set

• Current 3pcc reproduces centralized control model of xGCP or PSTN (but needed for SIP interworking with H.323, RTSP, HTTP, etc.)

• Make 3pcc distributed

Softphone directs my phone to dial, etc.

• Use request vs. control model

• Get status via notifications

3Presentation_ID © 1999, Cisco Systems, Inc.

Peer-to-peer 3pcc — ProposalPeer-to-peer 3pcc — Proposal

• If you can parse SIP URIs with method parameters and headers (needed for VoiceXML,

etc.) and...

• If you support REFER, turns out you have everything you need for “control”

• Use Refer-To URLs with method parameter

• SUBSCRIBE/NOTIFY is a reasonable way to get status

4Presentation_ID © 1999, Cisco Systems, Inc.

Next stepsNext steps

• Come up with SIP-Status event

• Choose REFER, PHONECTL, or some new method

• Choose authentication model

• Does this fit in call control framework?