This Recommendation defines the signalling interworking between the Bearer Independent Call Control (BICC) protocol and H.323. It defines in particular the signalling interworking between the BICC protocol and the H.225.0 Multimedia Call Control protocol in an H.323 network based on the interworking between H.225.0 and the ISDN User Part (ISUP) protocol of Signalling System No. 7. The interworking between H.245 and BICC is for further study (some aspects are addressed in 6.3 and Appendix I). BICC is the protocol defined in ITU-T Recommendations Q. 1902.1 to Q. 1902.4 [5]. The Multimedia Call Control protocol is defined in ITU-T H.225.0 [i] for a network in accordance with ITU-T H.323 [3]. ISUP is the protocol defined in ITU-T Recommendations 4.761 to 4.764 [4]. The description of the signalling interworking between the H.225 .O Multimedia Call Control protocol and the BICC protocol in this Recommendation builds upon: The signalling interworking between the H.225 .O Multimedia Call Control protocol and the ISDN User Part (ISUP) protocol of Signalling System No. 7 as defined in Annex CíH.246 [2]. The signalling interworking between the Bearer Independent Call Control (BICC) protocol and the ISDN User Part (ISUP) protocol of Signalling System No. 7 as defined in ITU-T Q.1912.1 [6]. The scope of this Recommendation with regard to the signalling interworking between the H.225.0 Multimedia Call Control protocol and the BICC protocol is as shown in Figure 1.