PacketCable

Abstract: Presently described is a system and method for switching multimedia data communications, including but not limited to Voice over IP (VoIP) telephony, cable TV, digital audio and video. The system utilizes a single, integrated device to provide all PacketCable-compliant functionality, including enhanced user privacy, compliance with CALEA, E911 and other mandated services not available in conventional distributed PacketCable systems. High speed and efficient, low cost operation are provided by means of an optimized data unit encapsulation scheme for internal switching and routing. A proprietary fiber optic backplane and removable optical connectors are used to enable lightspeed internal communications hot-swapping of components. Furthermore, the present system is extensible to all forms of digital data switching and is secure, resistant to Denial of Service attacks, and fault-resilient.

Abstract: A method of providing call admission control which does not require using MIDCOM protocol methods, Packetcable protocols or COPS-RSVP s approaches is described which is simple to implement, cost-effective and which is able to deal with particular situations such as conference calls. Each link in a communications network over which it is required to perform call admissions control is provided with a middlebox connected at each end of that link such that admissions control can be carried out at one end of the link. Call services are provided by Call Servers, each of which has access to a database containing pre-specified information about all middleboxes in that call server's realm. The database also has information about maximum bandwidths for the link associated with each middlebox. The call servers are used to keep a running tally of the amount of VoIP call bandwidth associated with each middlebox on the edge of a low-bandwidth link, and to accept or refuse calls on the basis of the bandwidth information on a per-call basis.

Abstract: A technique is described to change the codec or MAC (message authentication code) size in a packet security unit for PacketCable communications during realtime voice transmissions is described. An algorithm that provides fast RC4 key advancing to prevent MIPS (millions of instruction cycles per second) overflow is used to perform codec or MAC size changes. The invention is performed without changing the keying material, where the sender and receiver must continue the RC4 encryption process from its state prior to the codec or MAC size change. A sender needs to preserve continuity of the timestamp across a codec change, since the timestamp reflects realtime. Changing the codec or MAC size is likely to change the frame parameters. To preserve continuity of the RC4 state and the timestamp across the codec/MAC size change, the sender TX and receiver RX generates a new frame number. The new frame number is applied to the first frame generated by the new codec or MAC size.

Abstract: The present invention provides a Cable Gateway for interfacing packet cable networks with Internet Protocol (IP) Multimedia Subsystems (IMS). The Cable Gateway includes an Embedded Multimedia Terminal Adaptor (E-MTA) Normalization function that includes translation software that normalizes E-MTA interfaces to appear to IMS as SIP user equipment and performs initialization, call signaling, registration, authentication and security. The Cable Gateway also includes a CMSS/Mw Normalization function that interiors calls going between the IMS and a Remote CMS and a Gate Controller function that implements signaling interfaces to a CMTS and allows the E-MTA Normalization function and the CMSS/Mw Normalization function to interact with the CMTS and normalizes call-flow protocols. The Cable Gateway also includes a Packet Cable Multimedia (PCMM) Policy Decision Point (PDP) function that implements a Packet Cable Multimedia interface and a PCMM Application Manager and a Go Proxy that monitors SIP messages to and from user equipment. The Cable Gateway also includes an Event Manager that implements an interface to a Packet Cable Record Keeping Server and supports the production of call-related events on the Cable Gateway.