The BFCPBIS working group is chartered to specify a revision of BFCP (RFC 4582) to support using both TCP and UDP as transports. The current version of BFCP only supports TCP, which when both endpoints are behind NATs or firewalls, has a lower success rate than using the ICE techniques with a UDP based transport for BFCP. The need for video endpoints to work in these types of environments is driving a strong need to support a UDP based transport as well as TCP.
This WG will create a revision of RFC 4582 which adds optional support for UDP to BFCP. The security when using UDP will be based on DTLS. The updated protocol will use an existing approach (e.g., stop and wait with a single outstanding transaction) to provide a reliable, congestion safe, and TCP friendly transport.
In addition to providing a way for dealing with the reliable delivery of client-initiated transactions, the updated protocol will also be able to deliver server-initiated transactions reliably when needed. The WG will research the size of messages used and decide if fragmenting a request or response over multiple UDP packets is required. The new protocol will be backwards compatible with RFC 4582 when used in TCP mode.
The BFCPBIS WG will coordinate closely with the MMUSIC WG to create a revision of RFC 4583 specifying how BFCP is signaled in SDP so that it supports UDP as well as TCP transports. This WG would ask the MMUSIC WG to add a milestone to create a revisions of RFC 4583 to address signaling the use of UDP in SDP. The WG will coordinate with International Multimedia Telecommunications Consortium (IMTC) and other industry fora.