end-to-end real-time multimedia service on such heterogeneous networking environments: (1) multi- media session establishment and negotiation that adjusts the difference in the capability of multimedia data processing at the end terminal nodes, (2) QoS- guaranteed connection establishment or resource reservation with connection admission control (CAC) in each heterogeneous subnetworks along the path. For the multimedia session establishment and negotiation among hetero- geneous multimedia terminals with different capability in audio/visual data processing, QoS-extended SIP (Q-SIP)/Session Description Protocol (SDP) should be used. Session Initiation Protocol (SIP) is a signaling protocol on the application-layer for managing sessions with one or more participants [5]. The session may be VoIP (Voice-over-Internet Protocol) telephone calls, real- time video conferences, or a real-time multimedia group game. SDP is used for describing multimedia sessions for the purpose of session announcement, ses- sion invitation, and other forms of multimedia session initiation [6]. In order to establish a multimedia communication session, SIP/SDP messages must be exchanged among participants to check the availability of participants, capa- bility of terminals, determination of media type, transport protocol, format of media, related network and port addresses [7]. After determination of parame- ters for a multimedia session, QoS-guaranteed connection for the session must be established between the participant's terminals. When the QoS parameters and traffic parameters for the multimedia session are determined via the exchanges of SIP/SDP messages between the end ter- minals, a network layer connection establishment in the connection-oriented subnetwork and a resource reservation with CAC should be provided. For the IP/MPLS transit network, the resource ReSerVation Protocol with Traffic Engineering extension (RSVP-TE) [8] can be used to establish an MPLS LSP for the multimedia session. In the non-connection-oriented subnetworks, 