This diagnostics page will issue a series of pings from client to server and transfer several blobs of data. Based on this data it will provide the latency in milliseconds and max transfer speeds achieved. This is a quick and easy way to identify the network performance without having to install any tools on the client or server. Using this tool you can gather baseline performance from various locations and determine expected response times given the users bandwidth and latency. This should be taken into consideration when planning and designing a CRM environment to provide the best user experience available.
To use the diagnostics page you can simply browse to the page by using the URL http://<YourCRMServerURL>/tools/diagnostics/diag.aspx and click the Run button to start the tests. This page is available for both CRM Online and On-Premise.
Image CRM 2011 Diagnostics Page