looSely-couPLed sIp deviCES
|Document||Charter||looSely-couPLed sIp deviCES WG (splices)|
|Title||looSely-couPLed sIp deviCES|
|IESG||Responsible AD||Gonzalo Camarillo|
|Charter edit AD||(None)|
|Send notices to||(None)|
Disaggregated media refers to the ability for a user to create a multimedia session combining different media streams coming from different devices under his or her control so that they are treated by the far end of the session as a single media session. Generally, a given participant uses a single device to establish (or participate in) a given multimedia session. Consequently, the SIP signaling to manage the multimedia session and the actual media streams are typically co-located in the same device. In scenarios involving disaggregated media, a user wants to establish a single multimedia session combining different media streams coming from different devices under his or her control. This creates a need to coordinate the exchange of the those media streams within the multimedia session. There are a number of existing mechanisms that can be used to coordinate different devices under user's control and to involve them in the call (e.g. Message Bus (Mbus) [RFC3259], Megaco [ITU-T H.248.1] and SIP 3pcc [RFC3725]). However, these mechanisms are intended to be used in "tightly coupled" scenarios. The use of all those mechanisms requires the presence of a "master" device. That is, at least one among the different devices under the control of the same user must support the control mechanism and be able to become a controller for the other devices in the call. Moreover, the "master" device is supposed to remain involved in the user's session for its entire duration given that performing a handover of the master role is typically cumbersome and sometimes impossible. The objective of this working group is to develop a framework for disaggregated media in "loosely-coupled" scenarios, where no single device needs to remain in the session for its entire duration and no single device needs to act as a master. Coordination among devices in this type of scenario is less tight than in the scenarios described above since they do not assume central elements with complete knowledge of the whole media session. While the framework may describe how to use existing mechanisms (e.g., the SIP REFER method) to coordinate devices, the working group will not develop new device coordination mechanisms. The framework may identify the need for new (non-device-coordination) mechanisms to enable the implementation of loosely-coupled scenarios. In case the need for such new mechanisms is identified, the working group will specify them. Specifically, the proposed working group will develop the following deliverables: 1. A framework document describing key considerations for the exchange of disaggregated media in SIP. The document will include use cases and examples. The document may indentify the need for new mechanisms or extensions to existing mechanisms. 2. Specifications of new mechanisms or extensions to existing mechanisms if the need is identified in the framework.