LTE TCP socket stability testing

RE: LTE TCP socket stability testing

Kai — Sat, 30 Mar 2019 04:21:03 GMT

Hi Sigurd

The problem has been identified. The Verizon SIM card seems to not have been activated. When using an activated iBasis card, the problem is gone.

Best,

Kai

RE: LTE TCP socket stability testing

Sigurd — Fri, 29 Mar 2019 13:59:52 GMT

You should also try to apply this errata workaround:

https://www.nordicsemi.com/DocLib/Content/Errata/nRF9160_EngA/latest/ERR/nRF9160/EngineeringA/latest/anomaly_160_17

RE: LTE TCP socket stability testing

Sigurd — Fri, 29 Mar 2019 09:15:50 GMT

[quote userid="73977" url="~/f/nordic-q-a/45311/lte-tcp-socket-stability-testing/179100"]I've added the above code in main.c. The error behavior has changed a bit. When the error occurs, instead of being hung there, it resets the whole board. -- what does this behavior change mean?[/quote]

Please try to add "CONFIG_DEBUG=y" in the prj.conf, and see if that stops the reboot.

RE: LTE TCP socket stability testing

Kai — Fri, 29 Mar 2019 05:15:42 GMT

enum error_type {
	ERROR_BSD_RECOVERABLE,
	ERROR_BSD_IRRECOVERABLE
};

static void error_handler(enum error_type err_type, int err)
{
	while (1) 
	{
		switch (err_type) {
		case ERROR_BSD_RECOVERABLE:
			printk("BSD ERROR: RECOVERABLE: %d\n", err);
			break;
		case ERROR_BSD_IRRECOVERABLE:
			printk("BSD ERROR: IRRECOVERABLE: %d\n", err);
			break;
		default:
			break;
		}
		k_busy_wait(1000000*2);		// 2s
	}
}

void bsd_recoverable_error_handler(uint32_t err)
{
	error_handler(ERROR_BSD_RECOVERABLE, (int)err);
}

void bsd_irrecoverable_error_handler(uint32_t err)
{
	error_handler(ERROR_BSD_IRRECOVERABLE, (int)err);
}

hi,

I've added the above code in main.c. The error behavior has changed a bit. When the error occurs, instead of being hung there, it resets the whole board. -- what does this behavior change mean?

My card is a Verizon SIM coming with older board (v.0.7.0). No sure if it has been activated or not.

Best,

Kai

RE: LTE TCP socket stability testing

Sigurd — Wed, 27 Mar 2019 23:44:09 GMT

Hi,

Are you testing with the iBasis sim card? If yes, did you register them at nrfcloud.com ?

It could be that you are getting a error returned from the bsdlib. Please add the error-handlers and printing of error codes to your main.c file. You can do it like this:

#include <zephyr.h>
#include <stdio.h>
#include <string.h>
#include <gps.h>
#include <sensor.h>
#include <console.h>
#include <nrf_cloud.h>
#include <dk_buttons_and_leds.h>
#include <lte_lc.h>
#include <misc/reboot.h>
#include <bsd.h>
#include "nrf_socket.h"
#include "orientation_detector.h"
#include <net/socket.h>
#include <sys/time.h>


#define TCP_HOST "45.33.53.75"
#define TCP_PORT 9090


#define LC_MAX_READ_LENGTH1 128
#define AT_CMD_SIZE1(x) (sizeof(x) - 1)

static const char subscribe[] = "AT+CEREG=2";
static const char psm_disable[] = "AT+CPSMS=0";
static const char normal[] = "AT+CFUN=1";
static const char success[] = "OK";
static const char status1[] = "+CEREG: 1";
static const char status2[] = "+CEREG:1";
static const char status3[] = "+CEREG: 5";
static const char status4[] = "+CEREG:5";

/* Interval in microseconds between each time LEDs are updated when indicating
 * that an error has occurred.
 */
#define LEDS_ERROR_UPDATE_INTERVAL      250000


enum error_type {
	ERROR_NRF_CLOUD,
	ERROR_BSD_RECOVERABLE,
	ERROR_BSD_IRRECOVERABLE,
	ERROR_LTE_LC
};



static int at_cmd1(int fd, const char *cmd, size_t size)
{
	int len;
	u8_t buffer[LC_MAX_READ_LENGTH1];

	printk("====AT send (%d bytes): %s\n", strlen(cmd), cmd);
	len = send(fd, cmd, size, 0);
	if (len != size) {
		printk("***ERROR: AT send: failed, ret=%d.\n", len);
		return -1;
	}

	for (int i=0; i<50; i++)		// wait for 5s
	{
		len = recv(fd, buffer, LC_MAX_READ_LENGTH1, MSG_DONTWAIT);
		if (len > 0)
		{
			printk("====AT receive (%d bytes): %s", strlen(buffer), buffer);
			return 0;
		} 
		k_sleep(K_MSEC(100));
	}
	printk("**********AT receive ERROR.\n");
	return -1;
}

/**@brief error handler. */
void error_handler(enum error_type err_type, int err_code)
{


//#if !defined(CONFIG_DEBUG)
//	sys_reboot(SYS_REBOOT_COLD);
//#else
	u8_t led_pattern;

	switch (err_type) {
	case ERROR_NRF_CLOUD:
		/* Blinking all LEDs ON/OFF in pairs (1 and 4, 2 and 3)
		 * if there is an application error.
		 */
		led_pattern = DK_LED1_MSK | DK_LED4_MSK;
		printk("Error of type ERROR_NRF_CLOUD: %d\n", err_code);
	break;
	case ERROR_BSD_RECOVERABLE:
		/* Blinking all LEDs ON/OFF in pairs (1 and 3, 2 and 4)
		 * if there is a recoverable error.
		 */
		led_pattern = DK_LED1_MSK | DK_LED3_MSK;
		printk("Error of type ERROR_BSD_RECOVERABLE: %d\n", err_code);
	break;
	case ERROR_BSD_IRRECOVERABLE:
		/* Blinking all LEDs ON/OFF if there is an
		 * irrecoverable error.
		 */
		led_pattern = DK_ALL_LEDS_MSK;
		printk("Error of type ERROR_BSD_IRRECOVERABLE: %d\n",
								err_code);
								EINVAL;

	break;
	default:
		/* Blinking all LEDs ON/OFF in pairs (1 and 2, 3 and 4)
		 * undefined error.
		 */
		led_pattern = DK_LED1_MSK | DK_LED2_MSK;
		printk("Unknown error type: %d err_code: %d\n",
			err_type, err_code);
	break;
	}

	while (true) {
		dk_set_leds(led_pattern & 0x0f);
		k_busy_wait(LEDS_ERROR_UPDATE_INTERVAL);
		dk_set_leds(~led_pattern & 0x0f);
		k_busy_wait(LEDS_ERROR_UPDATE_INTERVAL);
	}
//#endif /* CONFIG_DEBUG */
}


/**@brief Recoverable BSD library error. */
void bsd_recoverable_error_handler(uint32_t err)
{
	error_handler(ERROR_BSD_RECOVERABLE, (int)err);
}

/**@brief Irrecoverable BSD library error. */
void bsd_irrecoverable_error_handler(uint32_t err)
{
	error_handler(ERROR_BSD_IRRECOVERABLE, (int)err);
}



void main(void)
{
	printk("Application started\n");

	int err;
	int at_socket_fd;
	u8_t buffer[LC_MAX_READ_LENGTH1];


	// create AT socket
	at_socket_fd = socket(AF_LTE, 0, NPROTO_AT);

	// start modem
	at_cmd1(at_socket_fd, subscribe, AT_CMD_SIZE1(subscribe));
	at_cmd1(at_socket_fd, psm_disable, AT_CMD_SIZE1(psm_disable));
	at_cmd1(at_socket_fd, normal, AT_CMD_SIZE1(normal));

	// wait for LET connection ready
	printk("LTE connecting ...\n");
	while (true) {
		int bytes;
		bytes = recv(at_socket_fd, buffer, LC_MAX_READ_LENGTH1, 0);
		if (bytes) {
			buffer[bytes] = 0;
			printk("====AT receive (%d bytes): %s", bytes, buffer);
			if (!memcmp(status1, buffer, AT_CMD_SIZE1(status1)) ||
			    !memcmp(status2, buffer, AT_CMD_SIZE1(status2)) ||
			    !memcmp(status3, buffer, AT_CMD_SIZE1(status3)) ||
			    !memcmp(status4, buffer, AT_CMD_SIZE1(status4))) {
				break;
			}
		}
	}
	printk("\nLTE connected\n\n");


	// get server IP address
	struct addrinfo * server_addr;
	err = getaddrinfo(TCP_HOST, NULL, NULL, &server_addr);
	if (err != 0)
	{
		printk("***ERROR: failed to get server IP address\n");
		return 0;
	}

	// print server IP address
	{
		u8_t * p2 = &(((struct sockaddr_in *)server_addr->ai_addr)->sin_addr.s_addr);
		printk("server IP addr=%d.%d.%d.%d\n", p2[0], p2[1], p2[2], p2[3]);
	}

	// set server TCP listening port
	((struct sockaddr_in *)server_addr->ai_addr)->sin_port = htons(TCP_PORT);

	// create & bind TCP socket
	int tcp_socket_fd;
	{
		tcp_socket_fd = socket(AF_INET, SOCK_STREAM, 0);

		struct sockaddr_in local_addr;
		local_addr.sin_family = AF_INET;
		local_addr.sin_port = htons(0);
		local_addr.sin_addr.s_addr = 0;
		err = bind(tcp_socket_fd, (struct sockaddr *)&local_addr, sizeof(local_addr));
		if (err != 0)
		{
			printk("TCP sokcet bind err: %d\n\r", err);
			return;
		}
	}

	// connect to server
	while(1) 
	{
		printk("\nTCP connect()...\n");
		err = connect(tcp_socket_fd, (struct sockaddr *)server_addr->ai_addr, sizeof(struct sockaddr_in));
		if (err == 0)
		{
			printk("TCP connect() succeeded\n\n");
			break;
		}
		k_sleep(K_MSEC(1000));	// delay 1s
	} 

	// check modem status; send TCP data to server

	int loop = 1;
	while(1) 
	{
		// read AT socket to see if there is any data; with non-block mode read
		while (true) 
		{
			int bytes;
			bytes = recv(at_socket_fd, buffer, LC_MAX_READ_LENGTH1, MSG_DONTWAIT );
			if (bytes <= 0) 
				break;
			buffer[bytes] = 0;
			printk("====AT receive (%d bytes): %s", bytes, buffer);
		}

		printk("---------------------------------------- %d\n", loop++);

		// send AT command to check modem status
//		at_cmd1(at_socket_fd, "AT%XCBAND", AT_CMD_SIZE1("AT%XCBAND"));
		at_cmd1(at_socket_fd, "AT+CESQ", AT_CMD_SIZE1("AT+CESQ"));
		at_cmd1(at_socket_fd, "AT+CEREG?", AT_CMD_SIZE1("AT+CEREG?"));
		at_cmd1(at_socket_fd, "AT+CGDCONT?", AT_CMD_SIZE1("AT+CGDCONT?"));

		// send TCP data to server
#if 1
		static char buf[] = {"a"};
		static int len = sizeof(buf);
		err = send(tcp_socket_fd, buf, len, 0);
		if (err != len)
			printk("**********TCP send: error=%d.\n", err);
		else
			printk("====TCP send (%d bytes)\n", len);
#endif

		// sleep 10s
		k_sleep(K_MSEC(10000));
	}

	close(at_socket_fd);
	return 0;
}

RE: LTE TCP socket stability testing

Kai — Tue, 26 Mar 2019 16:14:33 GMT

hi Sigurd,

Here are my board information:

1) modem fw is mfw-m1_nrf9160_0.6.8-30.alpha.

2) board version is 0.7.0

3) carrier is Verizon. The signal strength is about -80db ~ -90db.

We have another board in China. It has the same problem. Its information:

1) nRF9160-NB-MFW_030_12_prealpha

2) board version is 0.8.2

3) carrier is China Mobile. The signal strength is about -85db ~ -95db.

Could the problem be related to the carrier registration? I guess, maybe some registration procedure is missed for my board or SIM card?

Best,

Kai

RE: LTE TCP socket stability testing

Sigurd — Tue, 26 Mar 2019 13:56:36 GMT

Hi Kai,

[quote user=""]1) is this a proper test case for testing LTE/network stability?[/quote]

Yes, I don't see anything wrong with the test description.

[quote user=""]2) is anything missed in the coding for correctly configuring the modem?[/quote]

I don't see anything wrong in your code. You can see how we configure the modem in the lte_link_control driver here. When it comes to TCP, you can find a sample for that in this fork.

[quote user=""]3) does the test result meet your expectation?[/quote]

No, the instability you are seeing is not expected behavior.

[quote user=""]4) has Nordic done similar testing?[/quote]

I'm running the code you attached, and I have not been able to reproduce the issue. I have been running the test for almost 2 hours now, and the loop counter is now at ~700. I will let the test run overnight.

I tested with modem fw: mfw-m1_nrf9160_0.6.8-30.alpha

What version of the modem fw are you using for the test?

Best regards,

Sigurd