Need a script or batch to ping across WAN and log results

We have a very relaxed policy WAN between two offices that needs to remain clear of heavy traffic.  Every so often I might have an application exceed what it should use and end up slowing everything to a crawl.  Unless there is another free solution that somewhere is aware of, I could use a simple script or batch to ping across the WAN (I am able to ping a computer) and then write the findings to a log if the time=>300ms for more than 5 replies (or something similar that could be tweaked).  I could then copy the solution and have it check for even worse, say time=>1000 and then use blat to email me the log.  The problem now is that I am unaware of any issues until users start complaining about slowness in certain areas.  By then it looks bad on me.  Thanks for the help!