[Serusers] Re: [Users] AVPs are lost on relayed INVITE errors

[Federico Giannici]

The problem is surely related to the retrasmission of the INVITEs and 
probably to the UAC module.

I was able to reproduce the problem (AVPs vanishing) by adding a delay 
of 3 seconds for every message received. In this way a caused a couple 
of retrasmission for each message. Moreover that occurred only to the 
calls to a PSTN gateway using by the UAC module for authenticatuion and 
 From substitution.

In this case the INVITE's AVPs are no more present when the INVITE is 
logged by the ACC module (even if they were present before entering the 
transaction engine).

If calls are made to other voip users (not using the UAC module) or if 
there is non INVITE retrasmission, the AVPs are correctly found.

BTW, I used the t_lookup_request() function to test if the message is a 
retrasmission. It turned out that that INVITE and BYE retrasmissions are 
correctly identified, but not the ACK retrasmission. I don't know if 
this is the correct behaviour.

I hope this information can be useful to find the problem.

Thanks.



Federico Giannici wrote:
> The mistery keeps increasing!
> 
> I have found that if I set an AVP in an INVITE message, then the same 
> AVP is logged in the ACCOUNTING of the corresponding ACK message!
> 
> But it is NOT in the ACK message before it enters the transaction engine 
> (with a t_relay()). So it is the transaction engine that "copies" the 
> INVITE AVPS to the ACK. Or the accounting routines use the AVPs from the 
> corresponding INVITE instead of the ACK ones.
> 
> Is this the expected behaviour?
> Why this happens?
> 
> Thanks.
> 
> 
> 
> Federico Giannici wrote:
> 
>> I'm still not able to make these errors reproducible.
>>
>> Now I found that the "AVPs vanishing" occours with 200 OK situations 
>> too. It seems to be related to packets retransmission. They occur when 
>> the following errors are logged:
>>
>> Nov 28 22:28:30 eowyn OpenSER[3010]: ERROR: t_newtran: transaction 
>> already in process 0x502bbc58
>> Nov 28 22:28:30 eowyn OpenSER[3010]: ERROR: sl_reply_error used: I'm 
>> terribly sorry, server error occurred (1/SL)
>>
>> These are generated by this classic code:
>>
>> if ( !t_relay() )
>>     {
>>     sl_reply_error();
>>     }
>>
>> Now I'm asking myself: is it correct to reply to a message that is a 
>> retrasmission? Shouldn't we simply ignore it? Couldn't it confuse the 
>> UAs?
>>
>> Thanks.
>>
>>
>>
>> Federico Giannici wrote:
>>
>>> Bogdan-Andrei Iancu wrote:
>>>
>>>> Hi Federico,
>>>>
>>>> use avp_print() (works only with debug=9)  in failure_route to 
>>>> inspect the list of present AVP. maybe you do not have the AVPs you 
>>>> are trying to log.
>>>
>>>
>>>
>>>
>>> But I set those AVPs in EVERY message received by the server.
>>> Moreover, I'm SURE they are there because before forwarding those 
>>> INVITEs with t_relay() I log the messages to syslog and the AVPs ARE 
>>> THERE.
>>>
>>> Then, when some kind of errors are received (488, 422, etc.) it seems 
>>> that those AVPs are "lost" by the transaction engine...
>>> But I'm not sure what conditions cause this lost.
>>>
>>> Bye.
>>>
>>>
>>>> Federico Giannici wrote:
>>>>
>>>>> Daniel-Constantin Mierla wrote:
>>>>>
>>>>>> Hello,
>>>>>>
>>>>>> have you set the flag to log missed transaction?
>>>>>> http://openser.org/docs/modules/1.0.x/acc.html#AEN407
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> No, I set the following:
>>>>>
>>>>> modparam("acc", "db_flag", 1)
>>>>> modparam("acc", "failed_transaction_flag", 1)
>>>>>
>>>>> But no "db_missed_flag".
>>>>> Anyway:
>>>>>
>>>>> 1) I don't want to log missed calls in a separate table.
>>>>>
>>>>> 2) The failed INVITEs are actually logged in the normal table, but 
>>>>> the AVPs I set are not logged (it seems that they are not found).
>>>>>
>>>>> In normal cases the AVP are correctly logged. Even in many error 
>>>>> cases (404, and so on) they are logged too. But in some cases, with 
>>>>> strange errors (488, 422), the AVPs are NOT logged (accounting is 
>>>>> done, but AVPs are "n\a")!
>>>>>
>>>>> Any explanation of this?
>>>>>
>>>>> Thanks.
>>>>>
>>>>>
>>>>>> Or is that the some avps are not any more stored for failed 
>>>>>> transaction? Maybe some snippets of your config will give us more 
>>>>>> hints about what happens there.
>>>>>>
>>>>>> Cheers,
>>>>>> Daniel
>>>>>>
>>>>>> On 11/26/05 14:04, Federico Giannici wrote:
>>>>>>
>>>>>>> I'm using OpenSER 1.0.0 on OpenBSD 3.7 amd64.
>>>>>>>
>>>>>>> I have a strange problem with the accounting: I set a couple of 
>>>>>>> AVPs for every message that arrives at the server. I'm sure they 
>>>>>>> are there because they are written in the syslog logging. 
>>>>>>> Sometimes, when an INVITE is relayed (with transactions) and 
>>>>>>> receives an error (488, 422, etc.), in the SQL logging there is 
>>>>>>> no more presence of the AVPs!
>>>>>>> Is this a known problem?
>>>>>>> How can I avoid this?
>>>>>>>
>>>>>>>
>>>>>>> Thanks.



-- 
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    |-                      giannici at neomedia.it
    |ederico Giannici      http://www.neomedia.it
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