While Jitter can be minimized and reduced through jitter buffers, this is not a magic solution.
- A buffer is a caching system for receiving data packets.
- A voice call is broken into data packets and sent over a network.
- A buffer on the other end can store packets.
Whereas latency measures delays to VoIP calls, jitter measures latency variance within a network. However, setting too large a buffer directly increases the latency of actions on the sender’s side being received by a user, so you need to be careful with the buffer size.
Depending on the size of the jitter buffer, out of sequence packets can be rearranged before being delivered. However, this does introduce some delay in addition to the original latency on the network.
- Increasing the buffer size directly increases the delay of actions to the receiving end.
- Likewise having a buffer be too small can lead to call degradation as an excessive number of packets may be discarded.
So you need to be cautious in the size of the buffer. Generally, they are only effective for delay variations of less than 100 ms, and even then, deterioration in quality may be easily noticeable to users.
Bufferbloat
Another issue to be cautious of when using Jitter buffers is ‘buffer bloat’.
- Bufferbloat occurs when your router is unable to transmit all the packets required and builds up too large a queue (rather than dropping packets when the queue length starts making latency noticeable).
- This queuing causes large latency and bursts of jitter.
- The real-time nature of voice means that this is not helpful. Therefore organizations should try to identify the sources of jitter on their networks instead of relying on jitter buffers.
Network monitoring measures a nice selection of audio quality factors including Jitter, but provides a view to the private network, while businesses use inbound services to engage with customers from outside of their private network.
Phone number testing provides a wider variety and end-to-end perspective. Through the use of proactive monitoring and number testing, Spearline is able to alert issues that may have underlying jitter causes, rather than be overly reliant on jitter Buffers.