cloud_connect failed: -111

[Terje K Wahl]

Hi, the thread at https://devzone.nordicsemi.com/f/nordic-q-a/48859/nrf9160-dk-connecting-problems-with-nrf-cloud/211627 has been very useful for me to get past several problems getting the asset tracker example to work. I connect successfully to a NB-IoT network here in Norway now, thanks to (as explained in the linked thread) setting modem mode to NB-IoT, using legacy PCO mode and using a static IP address since DNS is not supported.

Finally, the problem I am left with is "cloud_connect failed: -111". I had high hopes that a certificate update (devzone.nordicsemi.com/.../nrf-cloud-certificate-update) would solve this, but after successfully updating my certificates the same problem still persists. 

I have a nRF9160 DK v 0.8.5, with modem FW updated. I can successfully connect to the network using the at_client sample. Since the SIM included with the dev. kit only supports LTE-M1 (no coverage where I am located), I am using a SIM card from com4.no to connect to NB-IoT.

Here is my output from the terminal:

***** Booting Zephyr OS build v1.14.99-ncs3-snapshot2-2647-gd6e67554cfeb *****

[00:00:00.378,173] 

[0m<dbg> nrf9160_gps.init: MAGPIO set: AT%XMAGPIO=1,0,0,1,1,1574,1577[0m

Asset tracker started

[00:00:00.389,282] 

[0m<dbg> nrf_cloud_transport.nct_client_id_get: client_id = nrf-352656100223414[0m

[00:00:00.398,498] 

[0m<dbg> nrf_cloud_transport.nct_topics_populate: shadow_base_topic: $aws/things/nrf-352656100223414/shadow[0m

[00:00:00.410,156] 

[0m<dbg> nrf_cloud_transport.nct_topics_populate: accepted_topic: nrf-352656100223414/shadow/get/accepted[0m

[00:00:00.421,661] 

[0m<dbg> nrf_cloud_transport.nct_topics_populate: rejected_topic: $aws/things/nrf-352656100223414/shadow/get/rejected[0m

[00:00:00.434,204] 

[0m<dbg> nrf_cloud_transport.nct_topics_populate: update_delta_topic: $aws/things/nrf-352656100223414/shadow/update/delta[0m

[00:00:00.447,082] 

[0m<dbg> nrf_cloud_transport.nct_topics_populate: update_topic: $aws/things/nrf-352656100223414/shadow/update[0m

[00:00:00.458,923] 

[0m<dbg> nrf_cloud_transport.nct_topics_populate: shadow_get_topic: $aws/things/nrf-352656100223414/shadow/get[0m

Connecting to LTE network. This may take several minutes.

[00:00:00.477,172] 

[0m<inf> lte_lc: Using legacy LTE PCO mode...[0m

[00:00:00.483,428] 

[0m<dbg> lte_lc.w_lte_lc_connect: Network mode: AT%XSYSTEMMODE=0,1,1,0[0m

[00:00:04.653,717] 

[0m<dbg> lte_lc.at_handler: recv: +CEREG: 2,"0CEB","0202791C",9,0,0,"11100000","11100000"[0m

[00:00:04.664,123] 

[0m<dbg> lte_lc.parse_nw_reg_status: Network registration status: 2[0m

[00:00:05.574,218] 

[0m<dbg> lte_lc.at_handler: recv: +CEREG: 1,"0CEB","0202791C",9,,,"11100000","11100000"[0m

[00:00:05.584,472] 

[0m<dbg> lte_lc.parse_nw_reg_status: Network registration status: 1[0m

Connected to LTE network

[00:00:05.595,123] 

[0m<dbg> nrf_cloud_transport.nct_connect: IPv4 Address 52.54.149.10[0m

cloud_connect failed: -111

LTE link disconnect

Shutdown modem

***** Booting Zephyr OS build v1.14.99-ncs3-snapshot2-2647-gd6e67554cfeb *****

...

Any other suggestions would be greatly appreciated.

Kind regards,

Terje

[Didrik Rokhaug]

Hi.

The mqtt_socket library merges all errors on connecting to -111 (connection refused).

However, the reason for your failure to connect might be other things than just some issue with the certificates.

Can you add a print inside the "if block" ncs/nrf/subsys/net/lib/mqtt_socket/mqtt.c:322 that prints the value of err_code?

AWS (which nRF Cloud) is built upon uses load balancing, so the IP address of the endpoint you are looking for might change without warning.

Best regards,

Didrik

[Terje K Wahl]

Further debugging shows that the call in nrf91_sockets.c inside nrf91_socket_offload_connect() hangs for quite a few seconds and then returns the timeout error when calling nrf_connect().

I'm not able to debug this further as it then goes into debugging assembly code...

Do you know how to increase timeout values for the modem establishing the TLS connection?

[Didrik Rokhaug]

I do not think it would help to increase the timeout.

Can you try to run the mqtt_simple* and ntp samples?

Both use DNS by default, without a simple option to disable it, but it should not be too hard to convert them. I've added the code used by the nrf_cloud library when a static IP is used.

If you are not able to get the mqtt_simple or ntp samples to work either, a modem trace might help us find the error.

#if defined(CONFIG_NRF_CLOUD_STATIC_IPV4)
/* Partly copy/paste from zephyr/subsys/net/ip/utils.c
 * Cannot be used when BSD library selects NET_RAW_MODE
 */
int af_inet_addr_pton(sa_family_t family, const char *src, void *dst)
{
	if (family == AF_INET) {
		struct in_addr *addr = (struct in_addr *)dst;
		size_t i, len;

		len = strlen(src);
		for (i = 0; i < len; i++) {
			if (!(src[i] >= '0' && src[i] <= '9') &&
				src[i] != '.') {
				return -EINVAL;
			}
		}

		(void)memset(addr, 0, sizeof(struct in_addr));

		for (i = 0; i < sizeof(struct in_addr); i++) {
			char *endptr;

			addr->s4_addr[i] = strtol(src, &endptr, 10);

			src = ++endptr;
		}
	} else {
		return -ENOTSUP;
	}

	return 0;
}

int nct_connect(void)
{
	int err;

	struct sockaddr_in *broker =
		((struct sockaddr_in *)&nct.broker);

	af_inet_addr_pton(AF_INET, CONFIG_NRF_CLOUD_STATIC_IPV4_ADDR,
		&broker->sin_addr);
	broker->sin_family = AF_INET;
	broker->sin_port = htons(NRF_CLOUD_PORT);

	LOG_DBG("IPv4 Address %s", CONFIG_NRF_CLOUD_STATIC_IPV4_ADDR);
	err = nct_mqtt_connect();

	return err;
}

* If you are using v1.0.0, note that the MQTT broker has changed hostname from iot.eclipse.org to mqtt.eclipse.org

[Terje K Wahl]

After struggling quite a bit to get network traffic going for NB-IoT using other simpler examples as you suggested, I've contacted our SIM card provider (Com4 in Norway). They are telling me I need to change the APN from the default "com4" to "iot.com4.net". I am however having trouble doing this (APN change won't be saved), so I found it best to create a new thread to ask for help regarding changing APN:

https://devzone.nordicsemi.com/f/nordic-q-a/53364/unable-to-change-apn

[Terje K Wahl]

Success! I Network traffic now works, and the asset tracker example (tested on the master branch) now works.

The problem turned out to be the network provider not having configured my SIM card/subscription to allow it to use NB-IoT. And also not telling me about this the first time I contacted them...

After this configuration change with the network provider, the correct APN is automatically used for context CID 0.

The problem was confising me because I registered and received an IP address on the network. So it was far from obvious that the problem was with the cellular subscription configuration.

DNS now also works. So please note: DNS problems can be because network traffic does not work in general.

Thank you for your help.

Kind regards,

Terje

[Didrik Rokhaug]

Hi.

Great to hear that everything now works.

If you have any further questions, feel free to open a new ticket.

Have a great day!

Didrik