TCP window size decreases during streaming

[venugopal_pai]

Hi everybody,
We have developed an embedded HTTP tunneling server to stream to VLC player. During streaming we have observed that the window size at the "server" end starts decreasing from 6432 and finally gives the "TCP->ZeroWindow" error.

Does anyone know why the window size becomes zero at the server end??
It happens even if we set it to a huge value using setsockopt().

Regards
Venu

[Lemog]

TCP Zero Window error message occurs when the TCP Window size on a machine remains zero for a specified amount of time. This means that when a receiving TCP returns an ACK with a 0 in the window field, it means the receiving socket buffer has filled. I would say to wait for few minutes or so and see if the issue continues or not.

[venugopal_pai]

Hi .
Thank you for the quick response.
We are doing live streaming currently and observing that the server receive buffer reduces to zero. The server only receives acknowledgments and hence we are not able to understand why the receive buffer should get full.

Is there any way to retrieve the buffer size from the kernel during run-time?
What may be the possible reasons for zero window size in this scenario?

Regards