None other than Winamp. Yes, that Winamp, Troy Jessup writes [1]:
"It seems that using Winamp with Shoutcast streams will let you know when your network is disconnected (Because the music will stop). ...
"When you are under a Bandwidth DoS Attack (The music gets choppy but still runs) ... "
Links:
[1] http://www.ndnn.org/blog/archives/000083.html