[lwip-users] Re: lwIP + PPP

[Iordan Neshev]

Message: 1
> Date: Mon, 29 Mar 2010 14:20:39 +0200
> From: Nicolas Dioli <address@hidden>
> Subject: Re: [lwip-users] lwIP + PPP
> To: Mailing list for lwIP users <address@hidden>
> Message-ID: <address@hidden>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Hello, i am using lwip 1.3.2 + PPP with FreeRTOS.
> I have a question about pppInProc.
> When i receive a ppp packet which start by 0x7E, when the function is 
> testing the fcs: he found an invalid fcs and drop the packet.
> I don't understand why ( i have already read rfc but i'm lost).
>
> perhaps, the packet is wrong: my sio_read return only the packet between 
> 2 flags 0x7E. An didn't return "CONNECT 115200" from the modem GPRS.
>
>   
Hmm, sio_read should not filter the input from the device. I'm using a 
GPRS modem too
and I don't have such problems. As a side note - I used to get bad fcs 
in the past and the problem turned out to be
incorrect UART port settings which resulted in big bit error rates for 
that baud rate.

Please make sure that every single character from the modem is delivered 
by sio_read() and tell us
if this helps.
Btw, Simon, this may be the same problem as yours.

Iordan.
> Nicolas Dioli
>
> Polytech'Nice-Sophia student
>