This Recommendation defines IP bearer control protocol (IPBCP), which is suitable for use in IP network environments where the Bearer Independent Call Control (BICC) protocol is deployed. IPBCP can be used also in other environments. BICC IPBCP is used for the exchange of media stream characteristics, port numbers and IP addresses of the source and sink of a media stream to establish and allow the modification of IP bearers. The exchange of information with IPBCP is done during BICC call establishment and after a call has been established. IPBCP uses the Session Description Protocol (SDP) defined in RFC 4566 [10] to encode this information.