Connection fail with only one operator (Signal strength ok)

I’m having a lot of trouble with my GPRS connection and Q2686 but only with one operator. It can sometimes connect, but most of the time, It fails. It doesn’t seem to be related to the time at which I try.
I’ve first though to the signal strength, but it’s 17, which should be good enough, no ? It can even drop below 12 with the other operators.

I’ve checked with 5 different ones (with different SIMs) and I can connect very easily with any of the 4, using the same modem. I’ve tried with another modem too. I’m always using the home operator.
The firmware is Fw7.1, but I tried with Fw7.4. Same problem.

I really want to understand what the problem could be, and if possible to correct it.
If any of you can help, I would be very grateful.

Here’s a connection trace:

at+cclk?
+CCLK: "09/10/01,11:33:06"

OK
at+wipcfg=1
OK
at+wipbr=1,6
OK	
at+wipbr=2,6,11,"apn"
OK
at+wipbr=2,6,0,"login"
OK
at+wipbr=2,6,1,"pass"
OK
AT+WIPBR=2,6,12,1
OK
at+wipbr=4,6,0
ERROR
at+cclk?
+CCLK: "09/10/01,11:33:06"

OK
at+ceer
+CEER: Error 234

OK
at+wipbr=4,6,0
ERROR
at+cclk?
+CCLK: "09/10/01,11:33:40"

OK
at+ceer
+CEER: Error 234

OK
at+wipbr=4,6,0
ERROR
at+cclk?
+CCLK: "09/10/01,11:34:11"

OK
at+ceer
+CEER: Error 234

OK

Here’s a few information:

at+creg?
+CREG: 0,1

OK
at+cops?
+COPS: 0,2,20810

OK
at+cops=?
+COPS: (2,"F SFR","SFR","20810"),(3,"Swisscom","SWISS","22801"),(0,"sunrise","sunrise","22802"),(0,"orange CH","ORANGE","22803"),(0,"F - BOUYGUES TELECOM","BYTEL","20820")

OK
at+cced=0
+CSQ: 17,0

+CCED: 208,10,296a,6b09,2,124,30,,,0,,,0,208,10,296a,1d1f,2,118,20,208,10,296a,,3,94,21,208,10,296a,,1,115,22,208,10,296a,f144,2,694,20,208,10,296a,,4,746,14,208,10,296a,595a,1,668,10,13

OK
at+wmbs?
+WMBS: 5,0

OK
ati0
 WAVECOM WIRELESS CPU

 MULTIBAND  900E  1800

OK
ati3
R71a01gg.Q2686H 2076692 052808 20:08

OK

https://forum.sierrawireless.com/t/faq-forum-wiki/3491/4

Ok, sorry,

I’ve got

at+wipbr=4,6,0
+CME ERROR: 812
at+ceer
+CEER: Error 234

812 means:“bearer connection failure: GPRS network failure”. Which not quite clear to me…
Does it mean that the network coverage is too poor and that I can’t really rely on the CSQ to guess if it is ?

Are you getting GPRS registered OK - ie +CGREG: 0,1

If so, this shows that you have no radio-related problems.

More likely, the problem is with your “APN”

Have you tried using just the standard AT Commands (no WIPSoft) to see if that works, or if it narrows down where the failure occurs?

Have you spoken to your Distributor - they should be aware of any specific local issues with particular local services…

The unhelpful nature of WIP result codes has already been noted: Wip_berr_gprs_failed - #2 by awneil

See the ‘Examples’ Appendix at the end of the AT Commands Interface Guide - ther’s a section titled, “Full AT GPRS Commands Examples”

I’ve got «+CGREG : 0,1 »

Following example2:

AT+CGCLASS="CG"
OK
AT+CGDCONT=1,"IP","M2MINTERNET"
OK
AT+CGQREQ=1,1,4,5,2,14
OK
AT+CGQMIN=1,1,4,5,2,14
OK
AT+CGATT=1
OK
at+CGACT=1,1
+CME ERROR: 515

+CME ERROR: 3

Following Example1:

AT+CGDCONT=1,"IP","M2MINTERNET"
OK
ATD*99***1#
CONNECT 115200
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NO CARRIER

I’m usually using an OpenAT program, then, the error occurs as a callback to “wip_bearerStart”, which is the same point (After a similar wait).

The point is that sometimes I can connect with the very same hardware/procedure/parameters. That’s why I was at first thinking to a network issue, but that’s unclear because:

  1. The CSQ seems good
  2. The same behaviour occurred on 2 different places, 600Km away from each other!

I wanted to call my operator, but I needed to understand a little more before. I had to start somewhere, which was on this forum :slight_smile:
I’ll call him on Monday.

Thank’s Awneil.

With IP, there are several “networks” involved - and gateways between them:

  1. There is the GSM Radio network - this is where issues with the SIM, signal strength, etc occur;
  2. There is the gateway between the GSM network and the internet - this is where issues with your APN settings, etc, occur;
  3. There is the “gateway” between the internet and your “host” system(s) - this is where you get the “standard” internet issues with your ISP, firewalls, routers, etc (not specific to GPRS)

As previously noted, I guess that your problems are with the “APN settings” rather than any “radio” issues?