Resource control protocol No.1@ version 2 – Protocol at the Rs interface between service control entities and the policy decision physical entity (Study Group 11)
This Recommendation provides the stage 3 specification of the protocol at the interface between service control entities (SCEs) and the policy decision physical entity (PD-PE). The functional requirements and the stage 2 specifications for this interface are contained in clause 8.1 of [ITU-T Y.2111] and in [b-ITU-T Q-Sup.51]. This interface is used to control session-based policy. Using the protocol specified in this Recommendation@ the SCE can: ?provide information to the PD-PE to identify media flows and their required QoS resource characteristics (e.g.@ QoS class@ bandwidth@ priority); ?provide service priority information to the PD-PE to facilitate appropriate priority handling; ?request resource usage information through the PD-PE for charging; ?provide related service information to the PD-PE to facilitate appropriate dynamic firewall working mode selection; ?indicate whether the media should be enabled (i.e.@ gate opened) when resources are reserved; ?in those instances where the media should not be enabled as soon as the resources are reserved@ i.e.@ may request that the gate be opened later; ?in the case where a NAPT function is required@ request address mapping information so it can do any modifications that may be required to address information within application signalling (e.g.@ SDP); and ? in the case where a path-coupled resource reservation mechanism is used@ indicate to the PD-PE whether it wishes to be notified when reservations are obtained and released. When an authorization token mechanism is used@ the PD-PE may supply the SCE with one or more authorization tokens which the SCE shall include in application signalling to the CPE.