Use Winsock insde DShow Filter

I am trying开发者_开发技巧 to develop a DirectShow filter with internet access.

When I try to use Winsock,

1) In TCP, I wait connections but cannot access to server (try with Telnet) and

2) In UDP in data wait step (recvfrom(...)) program breaks.

Is it not possible? Or do I have to change library settings for the filter?

Do you remember to call WSAStartup before creating sockets?

Also do you check your return values from calls such as "socket"? Its definitely not returning an INVALID_SOCKET?