[lwip-users] LWIP 1.3.2 + PPP

[Sirjee Rooplall]

Hi Support,

 

I am using LWIP 1.3.2 Atmel AVR32 UC3A port, and in particular I am using PPP.

 

Normally everything works fine, but I have ecountered a scenario which cause a problem and I I don't know where to start to fix it.

 

I collect data from a serial port, and I send this data through the PPP interface through a modem to our server.

 

At the application layer I call netconn_write to send the data, and I check the return flag of netconn_write and if the data was written correctly, then I clear a blocking flag which the serial port looks at in order to determine whether it can send more data.

 

I can see the pppifOutput is called by the tcpip_thread to send the data. But some how when I encounter the scenario where I am busy sending one packet and netconn_write has returned data sent OK, but PPP is still busy sending, I then write the second packet through netconn_write, and my packet does not reach the server, and I see PPP retries taking place i.e, pppifOutput is been called about three times.

 

1. Are there any rules that I should follow when I want to send multiple data packets?

2. Is it possible to send and receive at the same time through the same connection handle?

 

Kind Regards,

 

Sirjee Rooplall
Figment Design laboratories (Pty) Ltd
mailto: address@hidden
Mobile: +27 (0)83 230 8466