cc3200 tcp socket keep alive

My TCP connectivity knowledge is a bit rusty. But this may be due to there being no need to send a keep-alive packet in the 5 minutes, as the server does not require it for this short period. Does the TCP recreate a new connection when you attempt another request? This will let you know if the keep-alive has expired.

Glenn.

I do not recreate a new connection .
I use the keep-alive package for testing abnormal disconnect.
Such as the client of 3200 has disconnected with the server, because the server has been shut dowm abnormally.But the client of 3200 thought that it is connecting with the server.So the client of 3200 is unuseful.

I mean the keep-alive can test the abnormal disconnect,and disconnect with the server by itself.

I understand. But the time interval of sending keep-alive packets is variable, this is not set within the TCP RFC. So this is up to the implementation to decide.

For example from here - ltxfaq.custhelp.com/.../tcp-keepalives-explained

Typically TCP Keepalives are sent every 45 or 60 seconds on an idle TCP connection, and the connection is dropped after 3 sequental ACKs are missed. This varies by host, e.g. by default Windows PCs send the first TCP Keepalive packet after 7200000ms (2 hour)s, then sends 5 Keepalives at 1000ms intervals, dropping the connection if there is no response to any of the Keepalive packets.

Glenn.

Hi,

The CC3200 will send keep alive packets every 5min if there is no activity on the socket.
It might be that the server side is sending keep alive packets as well, in that case CC3200 will not send it's own keep alive packets since there is no need and in order to save power.

Thanks,
Alon

Hi Alon,
Thank you first,
I want to know that would the socket send keep alive ,in lpds mode?
I test send,recive,select,can wake up the system.
can the keepalive wake up the modul?

Hi,

    So,if i set the socket as recive time out , if there is no data , can it wake up the LPDS mode?

    sl_SetSockOpt(tcpclient_iSockID,SL_SOL_SOCKET,SL_SO_RCVTIMEO, (_u8 *)&timeVal, sizeof(timeVal));    // Enable receive timeout

   

   while(1)
   {

        iStatus = sl_Recv(tcpclient_iSockID, recv_buf, TR_BUFF_SIZE, 0);//SL_POOL_IS_EMPTY

Hi,

I am closing the thread, if issue still exist please open a new thread and add a link to this one for reference

Thanks,
Alon

Hi Alon

e2e.ti.com/.../2007675

I have different issue(If I have a blocking sl_accept, how can i restart the NWP without crashing.)
- But I would like to know if "keep alive timeout" could be used as a solution in this scenario

Thanks a lot
av

Hi av,

No, this is not solution for you. In this thread is discussed absolutely different thing. You cannot achieve fastest response by writing off topic questions.

As I wrote you at first thread, non blocking sockets are best way for you if you don't need use sleep modes.


Jan