registration and keepalives on iOS

[john.gathm@xxxxxxxxx (John Gathm)]

Hi,

using the provided keepalive function on iOS in pjsua/pjsua_app.c

void keepAliveFunction(int timeout)
{
    int i;
    for (i=0; i<(int)pjsua_acc_get_count(); ++i) {
	if (!pjsua_acc_is_valid(i))
	    continue;

	if (app_config.acc_cfg[i].reg_timeout < timeout)
	    app_config.acc_cfg[i].reg_timeout = timeout;
	pjsua_acc_set_registration(i, PJ_TRUE);
    }
}

I noticed in my server logs that pjsip kept re-registering itself,
therefore causing "log noise"
I just wondered why this pattern of re-registering was choosed over
the other pattern that I found,
actually just sending PJSIP_TCP_KEEP_ALIVE_DATA,which is "\r\n\r\n"
like in the pjsip/sip_transport_tcp.c:tcp_keep_alive_timer() function

(I understand that under iOS backrounding features, we had to use the
system provided keepalives rather than the pjsip native)

Is there any reason for re-registering itself at each keepalive ?

Regards,

John