One of the most interesting features of our WAN emulators is the ability to capture the latency and loss conditions from a live network and reproduce those conditions as they change second-by-second (actually up to 10x per sec.) in the lab. This is accomplished using separate piece of software called the Netropy Recorder or the Linktropy Recorder that runs on a PC on the live network and connects to any device on the other side of the network that responds to ICMP Echo (in other words, ping.)
Once the Recorder has run for long enough to capture the characteristics of interest, the time series is saved to a recording file, and that recording file can be imported into the Netropy or Linktropy emulator to replay those exact conditions in the lab.
While a Linktropy or Netropy device is needed for replay, the Recorder itself is available for free download from https://www.apposite-tech.com/technical/docs.html. By itself, it’s a useful troubleshooting tool to see how conditions are changing over your network. We find it especially useful to monitor network conditions over hotel wi-fi, airplane connectivity, and mobile networks.
Recording and replay is especially useful for emulating networks where the conditions can fluctuate rapidly such as 3G and 4G wireless networks and internet VPNs. In these situations, choosing a single value for latency or even a statistical distribution may not adequately capture the transient conditions that can interfere with the end-user experience.
Until now, the Recorder was only available for Windows, but Apposite has now released a version for Linux, tested on Fedora, Ubuntu, and Debian distributions. The installation package is available for free download at: https://www.apposite-tech.com/technical/docs.html or from the Netropy or Linktropy support website.
Give it a try and let us know what you think…