scope:

The present document describes a dynamic Quality-of-Service (QoS) mechanism for the IPCablecom project. It was issued to facilitate design and field-testing leading to the manufacture and interoperability of conforming hardware and software by multiple vendors.

IPCablecom is a set of protocols developed to deliver Quality of Service enhanced communications services using packetized data transmission technology to a consumer's home over the cable network. IPCablecom utilizes a network superstructure that overlays the two-way data-ready cable television network. While the initial service offerings in the IPCablecom product line are anticipated to be Packet Voice and Packet Video, the long-term project vision encompasses a large family of packet-based services.

The present document addresses requirements for a client device to obtain access to IPCablecom network resources. In particular, it specifies a comprehensive mechanism for a client device to request a specific Quality of Service from the DOCSIS® network. Extensive examples illustrate the use of the present document.

The scope of the present document is to define the QoS Architecture for the "Access" portion of the IPCablecom network, provided to requesting applications on a per-flow basis. The access portion of the network is defined to be between the Multimedia Terminal Adapter (MTA) and the Cable Modem Termination System (CMTS), including the DOCSIS^® network. The method of QoS allocation over the backbone is unspecified in the present document. Interface to the managed IP backbone and issues related to IP multicast are not within the scope of the present document. The present document also recognizes that per-flow reservations may be required within the customer premises, and the protocol developed addresses this potential need.

To summarize, the scope of the present document is:

• Allocation of QoS between the MTA and the CMTS.

• Specification of the interfaces which are available for control and delivery of QoS in IPCablecom Networks.

• Support for IPCablecom embedded MTAs.

• Support for Network-based Call Signalling (NCS) [3].

The present document assumes that DOCSIS^® QoS (specifically RFI version 1.1 [2] or later) is used to control and deliver QoS across the DOCSIS^® networks. Any reference to DOCSIS^® in the present document is understood to be DOCSIS^® version 1.1 or later.