Methods of establishing multimedia telecommunication (a multimedia “call”) between equipment (“terminals”). More particularly, the invention provides methods for reducing the time required to establish calls between terminals implementing ITU-T Recommendation H.324 and derived or related standards or recommendations such as 3G-324M. More specifically, it relates to methods and apparatuses for (i) concatenating H.245 messages to pass between the terminals at the start of the call to establish the capabilities of both terminals and agree on the type and format of media and data to be exchanged (ii) using non-standard H.245 messages or standard H.245 messages with non-standard fields to accelerate establishment and (iii) informing each terminal of the capabilities of the other and proposing the type and format of media and data to be exchanged by means of fields inserted in the call signaling protocol used for bearer establishment prior to the H.324 stage of the call.