SIM Cards not working on SMS modems

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mempson

13 posts

Geek

# 94007 4-Dec-2011 09:28

Hi

I am having issues with SIM cards on Data modems.
We use data modems to send and recieve SMS messages for remote monitoring and control.
I have found that in same cases, Prepay cards work fine until we do a top up and then we can not recievew SMS on the modem. The SIM cards do however work fine in a phone.

I recently had a case where a new prepay will not work on a 3G site but an on account SIM card will.

There are obviously some differences, but not sure what they are. I expect that we can overcome by initialisation settings on the modem if I knew what the doifferences were.

Any thoughts?

Best regards,
Mark.

johnr

19282 posts

Uber Geek
Inactive user

# 553374 4-Dec-2011 09:35

Hi Mark

Fault checking needs to be done at the modem level, I have seen many interesting things over the years,

Are you using modems purchased from China? We do not restrict 3G network access cause of the type of SIM or if that SIM is attached to a Prepay or Postpay connection

John

mempson

13 posts

Geek

# 555218 7-Dec-2011 21:09

I have just got a "faulty" SIM card back.
It worked fine on site until it was topped up, now it does not work.
I fitted it into a Samsung I5510.
It will receive texts in the I5510, but will not send them, including send to 777.
There is $23 credit and I can phone out on voice OK.

I then fitted it in a Samsung I9000 and it works fine.
I put another SIM into the I5510 and that works OK both send and recieve.

Any thoughts??

johnr

19282 posts

Uber Geek
Inactive user

# 555219 7-Dec-2011 21:14

Please answer my question above about the modems

John

mempson

13 posts

Geek

# 555223 7-Dec-2011 21:21

Hello John

One modem is a Contrive from Italy, the other is a Huawei modem from China.

johnr

19282 posts

Uber Geek
Inactive user

# 555224 7-Dec-2011 21:25

I have seen modems do funny things to SIM cards and kill them

mempson

13 posts

Geek

# 555237 7-Dec-2011 21:50

Recently, I have two clients who have had this issue. In both cases, it occured when they topped up the prepay SIM cards. They possibly removed the cards and topped them up in a phone.
In the first case, the SIM card was taken into a Vovofone shop and they replaced the SIM card and all worked well and is still working OK.
I have had a SIM card fail in a Vodem Stick a year or two ago.

So, there is no reason that the SIM card should change it's performance due to settings on the card or settings at the server?

If I take this SIOM card into a Vodafone shop, they will probably just replace it with a new one. The problem is that the site is an 11 hour driving round trip away. I would like to minimise the potential for future issues.
If there is a particular type of card or account that the client should use, I would like to give them the right advise.

Thank you and best regards,
Mark.

johnr

19282 posts

Uber Geek
Inactive user

# 555240 7-Dec-2011 22:01

Its not related to topping up, Its just not possible I know the preprod and production platforms, I work on them

I wonder if the SIMs are filling up with SMS and the modem is not deleting them,

SIM cards can die but when this happens the SIM would not register on the network

John

mempson

13 posts

Geek

# 555242 7-Dec-2011 22:08

Hi John

Thank you for your comments.

I have had a look on the SIM that works in one phone and not the other, and there are seven messages on the SIM that have not been deleted. The modems only delte them after the response has been sent.
I do not know if that is influencing the behaviour in the two phones.
I will see if I can delete them and get a different result.
- It looks like the top up is either just a coincidence or a time when some damage is done.

Thank you, Best regards,
Mark.

johnr

19282 posts

Uber Geek
Inactive user

# 555243 7-Dec-2011 22:10

Can the modem delete the SMS from Vodafone and other MSISDNs?

mempson

13 posts

Geek

# 555244 7-Dec-2011 22:13

I should be able to delete themusing manual instructions to the modem. I'll try tomorrow when I get back to work.

mempson

13 posts

Geek

# 556610 11-Dec-2011 15:04

Reports of two more problems with different modems failing when the prepaid SIM card is updated in another phone.

I have investigated one SIM card and some of the system control settings have been deleted including the SMS service number which should be +6421600600.

If I use the AT commands on the modem, I can set up the SMS service number in the modem and it then sends SMS messages.
It appears that when the SIM card is removed from the modem and fitted into a phone, and then the credit is updated, the SIM card is dynamically updated to change the control settings.

Best regards,
Mark.

mempson

13 posts

Geek

# 557285 13-Dec-2011 08:56

Having got hold of one of the "damaged" cards, I have done some analysis and am firmly of the belief that in the proces of updating the credit on the card, Vodafone New Zealand are dynamically altering the control settings on the card.
I found that the SIM card would recieve texts in Phone A but would not send them. It would send and recieve texts in phone B. An unaltered card would send and recieve in both phones.
To rejuvinate the SIM card, I fitted the card to a phone, (a Samsung GT I5510) and checked all the APN settings. - I did not alter anything, but after that I was able to send and recieve texts from this phone. Checking the APNs updated something on the SIM card.
I refitted the card into the modem, but it would still not send TXT messages. I discovered that the SMS service center number on the card was blank, so I used the AT+CSCA command to reset the service enter number back to +6421600600 and the modem burst into life. This appears to update the setting on the SIM card as well.

Phones purchased from Vodafone have these settings embedded in the firmware of the phone.
3rd party phones, modems, GSM controllers etc are totally reliant on the inhformation being on the SIM card.
If the information is dynamically removed, then the 3rd party equipment will no longer operate.

johnr

19282 posts

Uber Geek
Inactive user

# 557287 13-Dec-2011 09:00

mempson: Having got hold of one of the "damaged" cards, I have done some analysis and am firmly of the belief that in the proces of updating the credit on the card, Vodafone New Zealand are dynamically altering the control settings on the card.

Nope for a start the credit is not even on the SIM card its on the Vodafone Side of our Prepay platform that I help look after, Nothing is sent to the SIM from the network when a Prepay account is topped up.

If a SIM and handset are in New Zealand attached to it's home network (VFNZ) the SMS message centre number is not even used, You can set it to 12345678 and SMS would still send, The MSC number +6421600600 is only used now when the Vodafone NZ SIM is roaming (not attached to the home network)

mempson

13 posts

Geek

# 557309 13-Dec-2011 09:46

http://www.billingworld.com/blogs/baker/2011/04/real-time-provisioning-of-sim-cards-a-boon-to-gsm.aspx

johnr

19282 posts

Uber Geek
Inactive user

# 557310 13-Dec-2011 09:51

mempson: http://www.billingworld.com/blogs/baker/2011/04/real-time-provisioning-of-sim-cards-a-boon-to-gsm.aspx

Not sure what this has to do with Vodafone New Zealand and how prepay billing works,

Please note I have worked for Vodafone NZ coming up 12 years and work on the live Prepay charging platform