Ping and write the status of a timer on a GUI thread
As it is not really much code, let us just focus on the label part and a little naming.  


TimesBufferClear++;



If this is a variable, we should use camelCase casing for the name. If it is a property it follows the naming convention. 


currping  



Can be renamed to currentPingStatus, which is more meaningful.  

Now let us refactor the assignment to the Text property of this label:  

String formatPattern = "Current Buffer: {0} Clear: {1} Ping: {2} Buffer: {3}";

currentPingStatus.Text = String.Format(formatPattern,
         waveProvider.BufferedDuration.Milliseconds.ToString(),
         TimesBufferClear.ToString(),
         pingSender.Send(otherPartyIP.Address).RoundtripTime.ToString(),
         SendStream.BufferMilliseconds);