Binary Floor Control Protocol Overview
Unified Communications Manager supports presentation sharing using the Binary Floor Control Protocol (BFCP) for supported Cisco endpoints and third-party video endpoints. This feature lets users share a presentation within ongoing audio or video conversation.
The following example describes how presentation sharing works using BFCP:
An ongoing video conversation exists between two video phones. User A decides to share content with User B during the conversation. User A has the option to share the entire screen or share the specific application.
The BFCP stream allows User B to view User A's shared content.
An audio-video call with content share requires at least four channels: audio, main video, the second video, and BFCP control channel, to achieve video conferencing and sharing presentations in the second video channel. If the call parties are capable of Far-End Camera Control (FECC), a fifth channel must be established.
Presentation Sharing with BFCP
From release 12.5(1)SU3 onwards, for Unified Communications Manager registered SIP endpoints, the BFCP work when:
Two video-capable endpoints that start the conversation in audio-only mode share content during the call using BFCP support.
TRP is allocated during the call.
Presentation sharing using BFCP is supported only on BFCP enabled SIP networks. The entire network, including the endpoint devices and trunks, must be SIP.
Unified Communications Manager aids in the negotiation of the BFCP stream by relaying SIP messages between two endpoints.
This negotiation involves establishing a floor, which is a temporary permission to access shared resources.
The BFCP stream is a point-to-point stream between the endpoints. Unified Communications Manager is never a target of the BFCP stream.
The following figure provides an example of a complex video network with multiple Unified Communications Manager clusters. BFCP must be enabled on all the trunks and lines connecting the devices. For this network, BFCP must be enabled on the four SIP trunks and two SIP lines that connect the endpoints.
Unified Communications Manager rejects the BFCP stream in the following scenarios:
The Allow Presentation Sharing using BFCP check box on the SIP Profile page is unchecked for one of the SIP lines or trunks in the network.
One endpoint offers BFCP, but the other does not.
When the SIP line or SIP trunk uses MTP (non pass-through mode) or Transcoder.
BFCP control channel is always unencrypted. However, the presentation channel is encrypted if both phones are encrypted.