[lwip-users] LWIP PPP - When connecting, int sifup(ppp_pcb *pcb) is called multiple times

[Brian Stull]

I’ve been using the LWIP PPP stack for a while to connect to a cellular modem. It’s been working fine with one modem, but I’ve recently tried another modem (with another carrier) and the PPP sequence is not acting the same.

 

Specifically, what I’m seeing is that the fsm_rconfack() function is being called multiple times during the PPP negotiation which is then calling my PPP link callback function.

 

In fsm_rconfack():

 

    case PPP_FSM_ACKSENT:

       UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */

       f->state = PPP_FSM_OPENED;

       f->retransmits = pcb->settings.fsm_max_conf_req_transmits;

       if (f->callbacks->up)

              (*f->callbacks->up)(f);    /* Inform upper layers */

       break;

 

This case statement is being called which then tells my application that the PPP link is up. The problem is it is being called multiple times.

 

Any ideas is this is valid to be called multiple times?

 

 

-Brian