Which socket TCP or BSD

I wonder if you're asking about the specific TCPnet implementation supplied by Keil.

Historically, the TCPnet libraries only supported what I think you are referring to as the TCP API. It can be used both with or without the RTX.

It provides quite a lot of control, but my personal opinion is that it's not very 'programmer friendly'. For example, the TCP related functions are not re-entrant and the documentation states "All TCPnet-related functionality should be collected in a single networking task". Of course, limitations like these can be overcome, but it certainly took me a considerable time to feel I was controlling it reliably.

The BSD socket interface was added to TCPnet relatively recently. It attempts to implement a standard Berkeley Socket communication interface. But the documentation states that "These APIs are not a complete implementation of the BSD API". It sits on top of (and makes use of) the original networking facilities.

I have not used this BSD support, but as far as I am aware they are re-entrant, require the RTX and, being more standard, are more likely to be easier for someone to learn how to use them.

For any new project, it would probably be sensible to seriously consider using the BSD API.

I wonder if you're asking about the specific TCPnet implementation supplied by Keil.

Historically, the TCPnet libraries only supported what I think you are referring to as the TCP API. It can be used both with or without the RTX.

It provides quite a lot of control, but my personal opinion is that it's not very 'programmer friendly'. For example, the TCP related functions are not re-entrant and the documentation states "All TCPnet-related functionality should be collected in a single networking task". Of course, limitations like these can be overcome, but it certainly took me a considerable time to feel I was controlling it reliably.

The BSD socket interface was added to TCPnet relatively recently. It attempts to implement a standard Berkeley Socket communication interface. But the documentation states that "These APIs are not a complete implementation of the BSD API". It sits on top of (and makes use of) the original networking facilities.

I have not used this BSD support, but as far as I am aware they are re-entrant, require the RTX and, being more standard, are more likely to be easier for someone to learn how to use them.

For any new project, it would probably be sensible to seriously consider using the BSD API.

Thanks IB Shy, this was the answer I was looking for.

The interesting thing about the Berkeley socket interface is that almost all networking sample code on the net is for (or almost for) this API. And the majority of all network programming books describes this API and shows sample code for (or almost for) this API.

This is because the Berkeley sockets is the foundation for what later evolved into POSIX Sockets.

Note that the choice of API has nothing to do with the type of the remote host.