undeflow error

[Lawrence Anthony]

I have my pipeline working but the sounds drops after about 6 minutes giving me the follwoing error:j
651:gst_pulsering_stream_underflow_cb:<pulsesink0> Got underflow
0:09:59.888378651  3243      0x16c5780 WARN                   pulse pulsesink.c:651:gst_pulsering_stream_underflow_cb:<pulsesink0> Got underflow
0:09:59.988474708  3243      0x16c5780 WARN                   pulse pulsesink.c:651:gst_pulsering_stream_underflow_cb:<pulsesink0> Got underflow
0:10:00.022029367  3243      0x16c5780 WARN                   pulse pulsesink.c:651:gst_pulsering_stream_underflow_cb:<pulsesink0> Got underflow
0:10:00.122278723  3243      0x16c5780 WARN                   pulse pulsesink.c:651:gst_pulsering_stream_underflow_cb:<pulsesink0> Got underflow
0:10:00.589007916  3243      0x16c5780 WARN                   pulse pulsesink.c:651:gst_pulsering_stream_underflow_cb:<pulsesink0> Got underflow

Can someone tell me exactly what an underflow error actually is and perhaps how to fix it?