VoIP Jitter Definition

Jitter can damage call quality.

Jitter is the irregularity with which packets in a transmission arrive. This irregularity can damage sound quality, as VoIP (Voice over Internet Protocol) programs need to receive data at a regular pace.

Solution

To feed arriving packets to the decoding software at a regular interval, the VoIP system needs to maintain a buffer. The jitter buffer holds incoming packets and releases them for decoding at a regulated speed, eliminating jitter.

Drawbacks

The jitter buffer creates a delay in the delivery of packets, but the size of that delay depends on the size of the buffer. In most commercial VoIP, the jitter buffer is a set size and cannot be altered by the user--only turned on or off.

Causes

The irregularities in the arrival rate of the packets in a VoIP call are usually due to varying network load. Packets may not necessarily all follow the same route from caller to receiver, and this also can cause variability of receipt.

References

• Tip and Trick: Understanding Internet Line Quality Components: Ping, Packet Loss and Jitter