[Icecast] Newbie question: Poor transmission quality

[Mark Glassberg]

I am using Icecast2 with Ezstream, sending a playlist of mp3s.  The signal
quality is fine over my home network; but out on the internet it is poor,
with frequent interruptions and losses of connection. 

I would like to know which of the following two conditions, if any, can be
causing the problem.  First, I have a dsl internet service, with only 160k
upload capacity.  Second, my home network is connected to the dsl modem through
a router.

Any assistance would be greatly appreciated.