Quectel BC66, UDP, T-Mobile SIM in Germany: DNS parse failed

[Roalnd Baldin]

Hi,

unfortunatelly I can not connect to UDP server of T-Mobile Netherlands

In the following the key infos about my scenario:

• I am using the Quectel BC66-TE-B development kit
• I am working with a IoT sim card from T-Mobile Netherland in Germany.
• The roaming for Germany is activated for the sim card.
• The APN is set to: cdp.iot.t-mobile.nl
• The device get assigned the IP address : 10.0.0.191
• The command: AT+QIOPEN=1,0,“UDP”, “172.27.131.100”,15683,1001,1,1
• As the result I got the error response: +QIOPEN: 1,565
• The code 565 means: DNS parse failed

I tryed to execute AT+QIOPEN for IPv4 and IPv6. In both cases I got the same problem.

Actually I think that the IP 10.0.0.191 looks very very strange.

I can setup the IP address of the DNS server explicity. Does anyone know it??

Many thanks for your help!

Regards, Roland

[Roalnd Baldin]

… Now I got a diffrent IP 10.128.1.149. Still the same problem

[Stefan de Lange]

Hi, can you give us the full sequence of commands you use? That will help us find what is wrong.

[Roalnd Baldin]

Deactivate auto sleep mode

AT+QSCLK=0

Persistent setup

Set the band to band 8 (900 MHz) for Deutsche Telekom NB-IoT

AT+QBAND=1,8

Turn off the radio.

AT+CFUN=0

Set the APN

AT*MCGDEFCONT="IP","cdp.iot.t-mobile.nl"

Restart the module as some configurations only take place after a reboot.

AT+QRST=1

After reboot automatic dial-in to the network

F1: 0000 0000
V0: 0000 0000 [0001]
00: 0006 000C
01: 0000 0000
U0: 0000 0001 [0000]
T0: 0000 00B4
Leaving the BROM

AT+QSCLK=0
OK

+IP: 10.128.1.137

Open UDP socket and send message

Open the UDP socket to server

AT+QIOPEN=1,1,"UDP", "172.27.131.100",15683,1001,0,0
OK

+QIOPEN: 1,565

Get the last error with description

AT+QIGETERROR
+QIGETERROR: 565,dns parse failed

OK

The return from AT+QIOPEN should be +QIOPEN: 1,0

Many many thanks for your help!

Regards, Roland

[Stefan de Lange]

Hi, I am trying to reproduce this but my BC66 modem doesn’t even recognize the +QIOPEN command. So I am updating the FW first.

@Roalnd-Baldin said in Quectel BC66, UDP, T-Mobile SIM in Germany: DNS parse failed:

AT+QIOPEN=1,1,"UDP", "172.27.131.100",15683,1001,0,0
OK

+QIOPEN: 1,565

I notice you have a whitespace between ‘,’ and “172.27.131.100”. I can’t verify but I know some modems don’t like this and will fail.

[Roalnd Baldin]

Hi Stefan,

you are a cool guy!! This solved the problem. It was the whitespace.

Many many thanks for your support!!

Regards, Roland

[Roalnd Baldin]

Hi Stefan,

again many thanks. It works now. I can send data to my App. The following sequence works for Quectel BC66:

Deactivate auto sleep mode

AT+QSCLK=0

Persistent network and APN setup

AT+QBAND=1,8
AT+CFUN=0
AT*MCGDEFCONT="IP","cdp.iot.t-mobile.nl"

Restart the module as some configurations only take place after a reboot.

AT+QRST=1

After reboot wakup from sleep, deactivate auto sleep mode again and wait for network connect

AT+QSCLK=0

+IP: 10.128.0.134

Create a UDP socket and for UDP server

AT+QIOPEN=1,1,"UDP","172.27.131.100",15683,1001,0,0

Send message “Hello World”

AT+QISEND=1,11,48656c6c6f20576f726c64

[Stefan de Lange]

@Roalnd-Baldin Cool! Nice to see it works now.