VoIP Jitter Buffer Adjustment via RTP Header Modification
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Solution Overview
Problem
VoIP networks often suffer from jitter issues, particularly when receiving packets from external or wireless networks, which degrade voice call quality due to inadequate handling by local components.
Innovation Solution
The solution involves a device or system that modifies Real Time Protocol (RTP) headers of VoIP packets to adjust jitter buffer delay by dropping packets or modifying sequence and timestamp values, allowing for adaptive jitter buffering without decoding or re-encoding payload data, thus addressing excessive or insufficient jitter buffer delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a local jitter buffer is used to handle jitter in VoIP packets, then some jitter can be corrected up to a certain threshold, but large jitter from external networks cannot be properly handled and voice call quality degrades
Solution Approach 1:
The patent introduces a Session Border Controller (SBC) as an intermediary device between external VoIP networks and internal VoIP networks. The SBC performs jitter buffer delay adjustment by modifying RTP headers of VoIP packets, acting as a mediator that handles large jitter from external networks before packets reach internal components. This intermediary approach allows the system to handle jitter magnitudes that would otherwise overwhelm local jitter buffers.
Solution Approach 2:
The patent dynamically adjusts the jitter buffer delay parameter by modifying RTP header fields (sequence numbers and timestamps) of VoIP packets. By changing these temporal parameters, the system can increase or decrease the effective jitter buffer delay adaptively, allowing proper handling of large external jitter while maintaining compatibility with internal network requirements.
2Reliability
If RTP headers are modified to adjust jitter buffer delay, then jitter can be reduced or eliminated, but this requires processing that could potentially degrade voice quality or increase complexity
Solution Approach 1:
The patent extracts only the necessary header fields (sequence numbers and timestamps) for modification while leaving the packet payload intact. By selectively modifying only these specific fields in the RTP header and bypassing payload decoding or re-encoding, the system reduces processing complexity while achieving jitter buffer delay adjustment. This extraction approach avoids the complexity of full packet processing.
3Loss of time
If packets are dropped to decrease jitter buffer delay, then excessive delay can be reduced, but packet loss may occur which could affect voice quality
Solution Approach 1:
The patent modifies the temporal parameters (sequence numbers and timestamps) in RTP headers to reflect the desired jitter buffer delay adjustment. By changing these parameters mathematically rather than physically dropping packets, the system can decrease the effective jitter buffer delay without actual packet loss. This parameter transformation approach maintains voice quality while achieving the desired delay reduction.
Data Source
AI summary
The present invention includes devices, systems, and methods of Voice-over-Internet Protocol (VoIP) communication. For example, a method includes: receiving a data stream comprising a set of VoIP packets; and modifying a Real Time Protocol (RTP) header of at least one of said VoIP packets to modify a jitter buffer delay of said data stream. Optionally, the method includes decreasing the jitter buffer delay by: dropping at least one packet from said data stream; and decreasing a sequence number and a timestamp value in an RTP header of at least one additional packet subsequent to said at least one packet. Optionally, the method includes increasing the jitter buffer delay by: identifying a pair of consecutive packets in the incoming data stream, the pair of consecutive packets having consecutive sequence numbers; and increasing a sequence number in an RTP header of at least a latter packet in said pair of consecutive packets.