Sequence number retrieval for voice data with redundancy

A system for determining a sequence number indicating a position of a redundant payload of a voice data packet within a data stream, comprising:

• a payload history buffer;
• and
• a processor configured to:
• maintain, in the payload history buffer, a history of previously received timestamps associated with previous payloads, and previously received or derived sequence numbers associated with those previous payloads;
• unpack a primary payload, a sequence number associated with the primary payload, a timestamp associated with the primary payload, the redundant payload, and a timestamp offset associated with the redundant payload from the voice data packet and storing the sequence number associated with the primary payload and the timestamp associated with the primary payload in the history;
• calculate a timestamp parameter for the redundant payload based on the timestamp associated with the primary payload and the timestamp offset;
• calculate a time span of the data stream covered by the voice data packet using the timestamp offset;
• select a portion of the history based on the time span;
• compare the timestamp parameter to one or more of the timestamps in the selected portion of the history to derive a sequence number for the redundant payload;
• and
• update the history to include the timestamp parameter and derived sequence number of the redundant payload.

A non-transitory computer readable medium having stored therein processor-executable instructions that cause a processor to:

• maintain a history of previously received timestamps associated with previous payloads, and previously received or derived sequence numbers associated with those previous payloads;
• unpack a primary payload, a sequence number associated with the primary payload, a timestamp associated with the primary payload, a redundant payload, and a timestamp offset associated with the redundant payload from a voice data packet and storing the sequence number associated with the primary payload and the timestamp associated with the primary payload in the history;
• calculate a timestamp parameter for the redundant payload based on the timestamp associated with the primary payload and the timestamp offset;
• calculate a time span of a data stream covered by the voice data packet using the timestamp offset;
• select a portion of the history based on the time span;
• compare the timestamp parameter to one or more of the timestamps in the selected portion of the history to derive a sequence number for the redundant payload;
• and
• update the history to include the timestamp parameter and derived sequence number of the redundant payload.