PRTG is a Free IP SLA Monitor
Cisco's IOS based routers have a built-in QoS monitoring feature called "IP-SLA" which can - among other things - monitor the Quality of Service (QoS) between two Cisco switches: Cisco IOS based routers collect network information in real time: response time, one-way network latency, jitter, packet loss, packet delay, voice quality measurement, etc. You can use PRTG to monitor the resulting measurements. To this end, PRTG has a IP-SLA sensor, which converts PRTG into an IP SLA monitor and VoIP monitoring software.
Qos Monitoring – much more than just an IP SLA Monitor
However, in contrast to other network monitors and VoIP monitoring tools, PRTG offers more than the possibility to monitor IP SLA, which requires Cisco’s pricey hardware: With Paessler’s QoS sensors, you can monitor the network quality between any nodes you like (not only between routers). This way, you can monitor the QoS of any network structure without having to buy expensive IP-SLA capable hardware. The QoS sensors basically perform the same measurements as the IP SLA monitor, but you are not limited to monitoring connections between Cisco routers. Moreover, PRTG is not only a LAN monitor: using remote probes you can even monitor Quality of Service across VPNs and WAN connections.
PRTG – the free IP-SLA Monitor
Even the Freeware Edition of PRTG includes both the IP-SLA and QoS sensor. This edition, which allows you to monitor up to 10 sensors, is completely free for personal and commercial use.
PRTG Network Monitor is far more than a free IP SLA monitor. From a simple Ethernet performance test to complex bandwidth and availability monitoring, our network diagnostic tools help you to keep control of your network.
If you want to monitor more more than ten sensors, you will need a Commercial Edition. Licenses start at just $400 / €300. Thus, PRTG is most likely the cheapest commercial enterprise grade Qos and IP-SLA monitor. We have also created an iPhone application for PRTG, which makes mobile network monitoring possible. Moreover, Paessler offers the web load test tool Webserver Stress Test.