Re: PATCH: addressing an issue in smsc_at that makes the modem stop reporting incoming SMSes

Let's try again...

Best regards,
Andrija

Alexander Malysh wrote:
> Hi,
>
> it doesn't apply cleanly to current CVS. Could you please rediff?
>
> Andrija Petrovic wrote:
>
>   
>> I am sorry for messing up with the tabs-spaces issue.
>> The file should be correct now.
>>
>>  From Andreas Fink I have learned that there are problems in reading the
>> patch when I attach it as an ASCII file. So, I'm sending it gzipped.
>>
>> Best regards,
>> Andrija
>>
>> Alexander Malysh wrote:
>>     
>>> Hi,
>>>
>>> patch is OK and I'm willing to apply it BUT: you totally screwed
>>> indentation. Please use only spaces and not tabs. If you or any other fix
>>> indentation I will apply this patch to CVS.
>>>
>>> Thanks again for your patch.
>>>
>>> Andrija Petrovic wrote:
>>>
>>>   
>>>       
>>>> OK,
>>>>
>>>> here's the patch with original text. Once we fix this modem issue, I'll
>>>> propose another patch that will speed up the process of reading SMSes
>>>> from the memory (AT+CMGL instead of AT+CMGR).
>>>> Anyhow, I'm eager to provide my help/collaboration to make smsc_at work
>>>> in a stable manner.
>>>>
>>>> ================================================
>>>>
>>>> The main goal of the patch is to follow a simple rule:
>>>> "If the modem reports an error during SMS sending, don't retry the
>>>> sending, but ask it what it's got to say"
>>>>
>>>> So, any loops related to SMS sending are removed:
>>>>
>>>> 1. loop in at2_send_messages has been removed. Messages will be sent one
>>>> by one from the at2_device_thread main loop - while(!privdata->shutdown)
>>>> 2. loop in at2_send_one_message has been removed, so the single SMS
>>>> sending either succeeds or fails
>>>>
>>>> Consequences of the patch:
>>>>
>>>> 1. the define RETRY_SEND has been renamed to RETRY_WRITE (because it is
>>>> also used in writing a line to the modem), there is no RETRY_SEND any
>>>> more 2. the user needs to rely upon the sms-resend-retry mechanism -
>>>> this works fine AFAIK. E.g. put sms-resend-retry = 5 in the conf file.
>>>> Without such a line, kannel will not try to resend the SMS
>>>>
>>>> Best regards,
>>>> Andrija
>>>>
>>>> P.S.
>>>>
>>>> Long story short, the problem is in forcing the modem to send an SMS -
>>>> even if it reports an error.
>>>>
>>>> In the official Kannel version, there is a RETRY_SEND (equal to 3, in
>>>> smsc_at.h) define that defines how many times an SMS sending process
>>>> needs to be retried. It's  purpose is illogical - having a complete and
>>>> logical sms-resend-retry mechanism built in the Kannel logic.
>>>>
>>>> In the official Kannel version, if the software receives an error
>>>> response while trying to send the SMS, it simply tries again in a loop
>>>> (3 times, due to the value of RETRY_SEND). Such a behavior confuses the
>>>> GSM modem - on the first forcible SMS sending retry.
>>>>
>>>> If the software should report unsuccessful SMS sending through
>>>>  bb_smscconn_send_failed(privdata->conn, msg,
>>>> SMSCCONN_FAILED_TEMPORARILY, octstr_create("ERROR"));
>>>>
>>>> and let the modem "relax" (by asking it if there are new incoming SMS
>>>> messages pending) when it receives an error response from the modem, I
>>>> have seen that Siemens modems (TC 45, MC 39i) would never expose the
>>>> notorious issue.
>>>>
>>>> I have never encountered the issue in the last 15 months - since I
>>>> altered the logic within smsc_at.c. With the RETRY_SEND mechanism, I
>>>> have had the issue more than once daily (I operate the GSM modems in a
>>>> rather intense SMS traffic).
>>>>
>>>> Hope this comment will lead to a usable official version of smsc_at.c in
>>>> the future.
>>>>
>>>>
>>>> ===========================================
>>>>
>>>> Hillel wrote:
>>>>     
>>>>         
>>>>> Hi,
>>>>>
>>>>>  
>>>>>
>>>>> Andreas is keen to install it, but wants it to be re-sent.
>>>>>
>>>>>  
>>>>>
>>>>> Please put in the subject the word PATCH as otherwise it's not clear
>>>>> which mail is the patch.
>>>>>
>>>>>  
>>>>>
>>>>> thanks
>>>>>
>>>>>  
>>>>>
>>>>> *From:* Andreas Fink [mailto:[email protected]]
>>>>> *Sent:* 19 September 2007 11:48 AM
>>>>> *To:* Hillel
>>>>> *Subject:* Re: Feature request/wish for Kannel
>>>>>
>>>>>  
>>>>>
>>>>> ok so you want me to go through houndreds of mails to find the patch?
>>>>>
>>>>>  
>>>>>
>>>>>  
>>>>>
>>>>> On 19.09.2007, at 10:24, Hillel wrote:
>>>>>
>>>>>  
>>>>>
>>>>> Hi Andreas,
>>>>>
>>>>>  
>>>>>
>>>>> I think you should read what Andrija Petrovic wrote as it seems there
>>>>> are
>>>>>
>>>>> problems with both AT+CNMI operation and AT+CMGR.
>>>>>
>>>>>  
>>>>>
>>>>> Both patches seem to have been submitted but never implemented.
>>>>>
>>>>>  
>>>>>
>>>>> Rgds
>>>>>
>>>>>  
>>>>>
>>>>> From: Andrija Petrovic [mailto:[email protected]]
>>>>>
>>>>> Sent: 19 September 2007 10:09 AM
>>>>>
>>>>> To: [email protected] <mailto:[email protected]>
>>>>>
>>>>> Subject: Re: Feature request/wish for Kannel
>>>>>
>>>>>  
>>>>>
>>>>> Hi,
>>>>>
>>>>>  
>>>>>
>>>>> I'd better not answer directly to your direct question. Direct answer
>>>>> is
>>>>>
>>>>> "this patch has nothing to do with SIM card being filled up, but
>>>>> applying
>>>>>
>>>>> this patch will stop the SIM card from being filled up" :).
>>>>>
>>>>>  
>>>>>
>>>>> A complete answer should take into account the mode of operation of the
>>>>> AT
>>>>>
>>>>> modem.
>>>>>
>>>>>  
>>>>>
>>>>> 1. If the mode of operation is AT+CNMI (waiting for new message
>>>>>
>>>>> notifications), there is no reason why the modem should fill up the SIM
>>>>>
>>>>> card. Of course - with the current (unstable) version of smsc_at the
>>>>> SIM
>>>>>
>>>>> card used to fill up. Therefore, when I started working with Kannel,
>>>>> SIM
>>>>>
>>>>> overfilling was my primary concern. It turned out that once the modem
>>>>>
>>>>> started working correctly, with no "freezing" due to SMS send
>>>>> misbehavior,
>>>>>
>>>>> the SIM card never received a single SMS. All SMSes were consumed by
>>>>> the
>>>>>
>>>>> AT+CNMI mechanism (through +CMT notifications). When I say "never",
>>>>> that
>>>>>
>>>>> means 15 months on 3-4 modems synchronously, receiving up to 940
>>>>> SMSes/day,
>>>>>
>>>>> with peaks up to 30 SMSes/minute. (the figure of 30 SMSes/minute may be
>>>>>
>>>>> another topic for discussion, due to the hard limit of 10 SMSes/minute
>>>>> for
>>>>>
>>>>> sending...)
>>>>>
>>>>>  
>>>>>
>>>>> 2. If the mode of operation is AT+CMGR (reading the SMSes that reached
>>>>> the
>>>>>
>>>>> SIM card), my actual patch did not address this problem. This part of
>>>>>
>>>>> smsc_at will be a matter of my next patch. Mr Andreas Fink did not take
>>>>>
>>>>> advantage of the AT+CMGL command (listing all the SMSes in the SIM
>>>>> card).
>>>>>
>>>>> That command speeds up the process of reading the SMSes from the SIM
>>>>> card by
>>>>>
>>>>> at least an order of magnitude. In May of 2006 I submitted a rather
>>>>> large
>>>>>
>>>>> patch that solved this problem, but the patch never made it to
>>>>> submission.
>>>>>
>>>>> So, if you ask me, do not use the sim-buffering option for now.
>>>>>
>>>>>  
>>>>>
>>>>>  
>>>>>
>>>>> Best regards,
>>>>>
>>>>> Andrija Petrovic
>>>>>
>>>>>  
>>>>>
>>>>> P.S. Just as a curiosity - what do you use Kannel for? What is the
>>>>>
>>>>> exploitation scenario? Please, do not answer if it is a business secret
>>>>> or
>>>>>
>>>>> any type of confidential information.
>>>>>
>>>>>  
>>>>>
>>>>>  
>>>>>
>>>>> Hillel wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>>  
>>>>>
>>>>> Will your patch fix the problem with the SIM card filling up and not
>>>>> being
>>>>>
>>>>> cleared out and so new SMSs not being able to come in?
>>>>>
>>>>>  
>>>>>
>>>>> Thanks
>>>>>
>>>>>  
>>>>>
>>>>>  
>>>>>
>>>>>  
>>>>>
>>>>>  
>>>>>
>>>>>  
>>>>>
>>>>> Andreas Fink
>>>>>
>>>>>  
>>>>>
>>>>> Fink Consulting GmbH
>>>>>
>>>>> Global Networks Schweiz AG
>>>>>
>>>>> BebbiCell AG
>>>>>
>>>>>  
>>>>>
>>>>> ---------------------------------------------------------------
>>>>>
>>>>> Tel: +41-61-6666330 Fax: +41-61-6666331  Mobile: +41-79-2457333
>>>>>
>>>>> Address: Clarastrasse 3, 4058 Basel, Switzerland
>>>>>
>>>>> E-Mail:  [email protected] <mailto:[email protected]>
>>>>>
>>>>> www.finkconsulting.com www.global-networks.ch www.bebbicell
>>>>> <http://www.bebbicell>.ch
>>>>>
>>>>> ---------------------------------------------------------------
>>>>>
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>>>>>
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>>>>>
>>>>>  
>>>>>
>>>>>  
>>>>>
>>>>>  
>>>>>
>>>>>  
>>>>>
>>>>>  
>>>>>
>>>>>       
>>>>>           
>>>       
>
>