"Communication services utilizing the real-time transport protocol (RTP) as the application level framing protocol normally use a native IP-based transport mechanism [IETF RFC 3550]@ which results in using two separate user datagram protocol (UDP) ports for the RTP and RTP control protocol (RTCP) traffic components. ITU-T H.248 gateways provide a rich set of gateway services for such types of RTP traffic@ as defined by [ITU-T H.248.48]@ [ITU-T H.248.58]@ [ITU-T H.248.71]@ [ITU-T H.248.77]@ [ITU-T H.248.87] and [ITU-T H.248.88]. In addition@ multiple RTP-based traffic flow components could be multiplexed at multiple@ different levels (from the perspective of a layered protocol architecture). The purpose of this Recommendation is to clarify how ITU-T H.248 gateways support such ""multiplexing structures"". The scope of this Recommendation addresses the following subjects: ?C Terminology: clarification of RTP related terms and definitions; ?C Multiplexing methods: summary of existing multiplexing schemes in context of RTP-based communication services; ?C ITU-T H.248 support: provides information on how dedicated multiplexing methods could be supported by ITU-T H.248 gateways inclusive of references to relevant signalling syntax; and ?C Examples: provides some signalling examples as complementary information. This Recommendation does not define any new ITU-T H.248 protocol extensions."