Abstract: A device manages data for a digital signal processor. The device includes an external random access memory (RAM), configured to store channel specific data for plural different channels; and a microprocessor, in communication with the external RAM. When receiving the packet, in a transport layer processing the packet, the microprocessor determines a channel of the plural different channels corresponding to an indication in a transport layer header of the received packet. The microprocessor fetches channel specific data specific to the channel into an internal memory internal to the microprocessor from the external RAM, by the transport layer, before the packet is passed to an application layer, thereby avoiding a wait for reading the packet at the application layer.

Abstract: A device manages data for a digital signal processor. The device includes an external random access memory (RAM), configured to store channel specific data for plural different channels; and a microprocessor, in communication with the external RAM. When receiving the packet, in a transport layer processing the packet, the microprocessor determines a channel of the plural different channels corresponding to an indication in a transport layer header of the received packet. The microprocessor fetches channel specific data specific to the channel into an internal memory internal to the microprocessor from the external RAM, by the transport layer, before the packet is passed to an application layer, thereby avoiding a wait for reading the packet at the application layer.

Abstract: In order to reduce distortion in playout of audio received in a packet over a packet network, the playout unit needs to determine the relative delay of adjacent packets, jitter, present in the network. The jitter is used to determine buffering for smoothing playout of audio in a packet network. The jitter in packets received from a packet network is calculated based upon the arrival time of a packet, the length of the packet and the arrival time of a subsequent packet. The receiving gateway notes the arrival time of a packet. The length of the audio payload is determined from the size of the payload and the codec used to encode the payload. The length of the payload is added to the arrival time to determine the anticipated arrival of the next subsequent packet. The actual arrival time is noted and the difference between anticipated arrival and actual arrival is used to determine jitter.

Abstract: A method to reduce memory requirements for a packet loss concealment algorithm in the event of packet loss in a receiver of pulse code modulated voice signals. A voice playout unit in the receiver shares its nominal delay buffer with a history buffer of a packet loss concealment algorithm up to a maximum limit described in a standard. This reduces or eliminates need to allocate memory for the history buffer. A history buffer can also be extended to retain an original portion of voice signal packets received prior to a packet loss as well as generated voice signals as they are generated. A scratch buffer is used as a working buffer and replaces the function of a pitch buffer.