Jitter Noise

Jitter noise is one of the most common problems affecting the quality of VoIP phone calls. The network monitoring solution PRTG Network Monitor enables you to trace Ethernet jitter, configure alarms that will warn you if the jitter noise is reaching a defined threshold, and thus help you to proactively approach VoIP network troubleshooting.

How Does PRTG Measure Ethernet Jitter?

PRTG comes with a QoS (Quality of Service) sensor and an IP-SLA sensor. While the IP-SLA monitoring feature can only be used with IP-SLA enabled Cisco routers and switches, the QoS sensor can be used in any network. Both methods check parameters which are important for VoIP phone calls, such as jitter noise, packet delay variation, Ethernet latency, packet loss, delay,  etc.

What is Jitter?

Ethernet jitter describes the variability over time of the packet latency across a network. A network with a constant delay has no jitter. Phone conversations, are, however, still affected by packet delay, as the resulting delays in the conversation are generally perceived as irritating.

How to Reduce Jitter in Phone Connections?

Packet delay and Ethernet jitter noise can be reduced by prioritizing VoIP traffic in the network. Buying more bandwidth, changing cables, or turning off applications that consume a lot of bandwidth for the duration of the VoIP phone call can also help to reduce Ethernet latency and jitter. PRTG also monitors bandwidth usage, shows you which applications or IP address use most bandwidth, and thus enables you to identify bandwidth congestions before jitter affects your phone conversations.

In addition, the PRTG Network Monitors also check the performance and availability of your network devices (even across a WAN) and are indispensable for Windows network troubleshooting (XP, Windows Server 2003 and 2008, Windows 7 and Vista network troubleshooting). Thanks to the iPhone app iPRTG, mobile network monitoring is also possible: access the network port monitor from wherever you are.