ANSI SCTE 24-4 pdf free download

ANSI SCTE 24-4 pdf free download.IPCablecom 1.0 Part 4: Dynamic Quality of Service for the Provision of Real-Time Services over Cable Tel levision Networks Using Data Modems.
Enhanced Quality of Service is required for supporting interactive multimedia applications. Resources may be constrained in segments of the network, requiring allocation of resources in the network. The scope of this specification is to define the Quality of Service Architecture for the “Access” portion of the IPCablecom network. The access portion of the network is defined to he between the Multimedia Terminal Adapter (MTA) and the Cable Modem Termination System (CMTS), including the DOCSIS network. This specification also recognizes that per- flow reservations may he required within the customer premises, and the protocols developed herein address this potential need. Although some segments of the backbone network may require resource reservation to provide adequate quality of service, the protocols for backbone resource management are considered to be outside the scope of this specification.
Resources are allocated on the DOCSIS network for individual flows associated with each session of an application, per subscriber, on an authorized and authenticated basis. A DQoS session, or simply a session, is defined by this specification to be a single bi-directional data flow between two clients. When a multi-media application needs multiple bi-directional data flows (e.g., one for voice and a separate for video), separate DQoS sessions are established for each. Applications may use only half of the session’s bi-directional data flow, thereby providing send-only or receive-only services. For example, in a typical voice communications application, a simple communication between two parties is implemented by a single session, while complex, multiparty communications (e.g., “conference calls”) are implemented by multiple simultaneous sessions.
Network-based Call Signaling (NCS) is the defined IPCablecom Call Signaling Protocol. This Dynamic QoS specification is the underlying QoS framework for this call signaling protocol. QoS is allocated for flows associated with a session in concert with the signaling protocol.
This specification introduces the concept of a segment-by-segment QoS framework. It exploits the information available from signaling protocols to perform the QoS on both the “local” segment (on the DOCSIS network close to the originating party) and the “remote” segment (the DOCSIS network close to the terminating party). Thus, this specification allows different providers to use the most appropriate mechanisms for the segment that they are managing. Using a concatenation of the segments with QoS, end-to-end QoS assurance for the session is provided.
The Dynamic QoS specification incorporates protocols to enable providers of packet-based voice communications using the IPCablecom framework to use different charging models, including both flat-rate charging as well as usage-based charging. It is the intent of this specification to ensure that enhanced QoS is provided only to authorized and authenticated users. The specific techniques used for authorizing and authenticating a user are beyond the scope of this specification.
This Dynamic QoS specification recognizes the requirements of a commercially viable voice communications service analogous to that offered by means of the public switched telephone network. It is important to ensure that resources are available before the two parties involved in the session are invited to communicate. Thus, resources are reserved before the recipient of the communication is notified that someone is trying to initiate a communication. If there are insufficient resources for a session, then the session is blocked.ANSI SCTE 24-4  pdf download.