In Figure 1, HOSTB and HOSTC are composite network nodes connected by a VR-based TG (TG255). In this configuration, an LU-LU session between HOSTA and HOSTD can use an RTP connection that traverses the composite network nodes. HOSTB and HOSTC have no awareness of the session between HOSTA and HOSTD, as they are providing ANR-level support only. However, for sessions where HOSTB or HOSTC constitute one end of a session, HOSTB and HOSTC can provide RTP-level support (see Sessions through NCP in a composite network node providing RTP support for further details). HOSTA, as a network node, can also provide ANR-level support for sessions between HOSTB, HOSTC, or HOSTD and some other unpictured node. HOSTD, as an end node, cannot provide ANR-level support.