Method and system for transmitting information during call connections between a multiplicity of subscribers as components of traffic in an integrated services network (ISN), in which the information traffic consists of a multiplicity of media types according to the different subscribers including voice, video and data traffic component types. A plurality of traffic component types in the form of portions of information streams to be transmitted from subscribers at an entry point of the ISN during respective call connections are assembled into each of a sequence of composite frames of variable size for transmission through the ISN. The traffic component types assembled into each of the composite frames are limited to those destined for subscribers at the same exit point of the ISN. Each composite frame is configured with the traffic component types assigned to respective separate groups of adjacent channels of predetermined bandwidth with each group limited to channels transporting traffic components of the same type and each channel in a group dedicated to a particular subscriber of the respective traffic component type for the duration of its respective call connection. Bandwidth in the composite frames is selectively seized for reallocation among the various traffic component types during periods of traffic congestion.