ent function, while the ingress router must support the RSVP-TE server function. Since RSVP-TE establishes only unidirectional connection, two PATH-RESV message exchanges should be implemented to establish a bidi- rectional path between the user terminal and the ingress router [10]. The RSVP-TE UNI signaling message carries the QoS and connection parameters for the specified application data flows. RSVP-TE NNI signaling message is used by routers to deliver QoS requests to all nodes along the path in the IP/MPLS subnetwork, in order to establish and maintain the state to provide the requested QoS-guaranteed service. The routers should be able to reserve network resources according to the requested QoS and traffic parameters [11]. 15.3 Session Establishment for QoS-Guaranteed Real-Time Multimedia Service Provisioning on Broadband Convergence Network (BcN) 15.3.1 Q-SIP/SDP Interaction for End-to-End QoS Session Negotiation Figure 15.2 depicts the overall functional block diagram and interaction model of session and connection management in QoS-guaranteed multimedia service provisioning [10,12]. The user terminal will first discover available service from the service directory of the network operator that provides service profiles. The service subscription will define the service level agreement (SLA) of the © 2009 by Taylor & Francis Group, LLC Service level agreement Service discovery (SLA) Service Service Service negotiation & subscription/ subscription registration directory profile QoS-guaranteed Multimedia services Multimedia QoS-VPN QoS-VPLS application (service conference Service Diffserv service (e.g., MMoIP, Conference) configuration Parlay/OSA API, & management) Authenti- QoS-Virtual Policy-based Interaction with Distributed control server cation network management next AS & management of next hop AS Location Resource MMoIP session (autonomous Processing Distributed server Routing reservation system) setup & control (encoding, control & XML/SOAP, decoding) management Call/ connection Subnetwork/ COPS, SIP