Some of the coolest technology out there today is basically free - or at least something most of us have already bought and paid for but never used. I'm talking about Cisco's IP SLA which has also been called RTT and SAA. IP SLA is a feature within Cisco IOS that let's you use the router/switch as sort of a probe or agent out on the network. IP SLA can generate test traffic from these devices deployed out on your network to other devices out on the network giving you a sort of "fully meshed" view of network performance.
Some of the IP SLA operations include things like UDP Jitter, UDP Echo, ICMP, HTTP, and FTP. You can read about all of the different tests and features here. In situations where latency sensitve applications are deployed to remote locations - especially on for instance a fully meshed MPLS network - this information is a huge help.
We're planning a more detailed blog post and a short video on how to leverage IP SLA with SolarWinds tools. If you have some specific ideas or requests please send them my way.