0 relies upon the services of GCC and MCS to transmit control data. Although the T.130 suite addresses manipulation of real time streams within an established conference topology, it does not define mechanisms to set up that Standards for Audiographic Conferencing topology. Terminals are not required to implement the protocols referenced in T.130 to participate in the audio and video portions of a T.130-based conference. However, terminals that do not may have very limited options as they relate to audio and video control services. T.131 The formal title of the T.131 is Network Specific Mappings. Each network requires unique control mechanisms that manage audio and video streams. T.131 specifies the mapping between the network-independent control mechanisms of T.132/3 audio video control (AVC) and that of the active network. Network specific mapping mechanisms reside in a node controller. Given that AVC depends on the data services provided by T.120, it must provide for the inheritance of audio and video streams that are activated prior to the start-up of T.120. Defines interaction between AVC and H.245 in H.324 systems Defines interaction between AVC and H.242/3 in H.320 systems Defines interaction between AVC and H.245 in H.323 systems Defines interaction between AVC and H.245 in H.310 systems DSM-CC Defines interaction between AVC and DSM-CC DAVIC systems Figure 8-3. Networks supported by T. 131 T.132 The formal title of the T.132 is Audio Video Control: Infrastructure Management. The T.132 protocol performs operations that are needed by T.133, Audio-Video Control: Conference Services. T.132 specifies mechanisms for multimedia capabilities exchange (whereby terminals handshake and exchange information about the services that they support/require). It also defines procedures used to arbitrate access to the various channels and support mechanisms that, collectively, sustain a conference. T.132 characterizes the procedures used to configure and control the audio-visual infrastructure. The T.132 specification intr