[reSIProcate] SipStack not sending the message to correct address

[Janari Põld]

Thanks for the quick reply.

What is the correct solution?
Should I change the transaction ID every time
I resend the invite to another Server?
Is there any good solution to generate new
transaction ID?


Best Regards,
Janari Põld

Byron Campen wrote:
>     Simply changing the Request-Uri on the original request and 
> resending is invalid. This is because both requests will have the same 
> transaction id. It appears that there is a bug in 
> TransactionState::processClientInvite() that will allow 
> mMsgToRetransmit to be overridden by any request from the TU, 
> regardless of what state the transaction is in (ie, sending a new 
> INVITE with the same transaction-id is causing state-corruption in the 
> stack). This is what is causing the assert, and this probably should 
> be fixed to disallow override of mMsgToRetransmit.
>
> Best regards,
> Byron Campen
>
>> Hey,
>>
>> I am writing a SIP proxy using resiprocate library.
>> The proxy is running on 192.168.200.1 and
>> two SIP servers on 192.168.200.2 and 192.168.200.3.
>>
>> Following is the scenario that I want.
>>
>>   Client         Proxy      Server1      Server2
>>     |    INVITE    |           |            |
>> 1.  |  ----------> |  INVITE   |            |
>> 2.  |              |  -------> |            |
>>     |              |    500    |            |
>> 3.  |              |  <------- |            |
>>     |              |    ACK    |            |
>> 4.  |              |  -------> |            |
>>     |              |           |  INVITE    |
>> 5.  |              |  --------------------> |
>>     |            ..........                 |
>>
>> Step 1
>> Proxy receives invite from client, adds via and record-route
>> header and changes the request-uri (sets the Server1 ip address
>> in request-uri)
>>
>> Step 2
>> Proxy sends the invite to Server 1, using method
>> sendTo(SipMessage, Uri, TransactionUser) in SipStack.
>>
>> Step 3
>> Server1 responds with 500
>>
>> Step 4
>> Proxy (SipStack) sends automatically ACK to Server1.
>>
>> Step 5
>> During step 1 Proxy saved the received invite into memory and
>> now Proxy changes the request-uri (sets the Server2 ip address
>> in request-uri). Now if the Proxy tries to send the message to Server2
>> using sentTo(SipMessage, Uri, TransactionUser) method, the SIP message
>> is actually sent to Server1.
>>
>> Why is the stack sending the message to server1??
>>
>>
>> The Server1 responds again with 500 and after that the stack gets
>> Assertion Failure and the ABORT signal is sent to the proxy application
>> and the app shuts down.
>>
>> I added code to TransactionState.cxx method
>> processClientInvite(resip::TransactionMessage*) to print out
>> the msg and mMsgToRetransmit messages. Here is a snippet from the log.
>>
>> INFO | 20070302-175232.043 |  |  | RESIP:TRANSACTION | 0 | 3057712048 |
>> TransactionState.cxx:797 |
>> --------------------------- msg BEG ---------------------------------
>> SipResp: 500 tid=4b941154408e538aae1822d1ee5fa4ed cseq=INVITE
>> contact=192.168.200.2:5060 / 1 from(wire)
>> --------------------------- msg END ---------------------------------
>> INFO | 20070302-175232.043 |  |  | RESIP:TRANSACTION | 0 | 3057712048 |
>> TransactionState.cxx:798 |
>> --------------------------- mMsgToRetransmit BEG
>> ---------------------------------
>> SipReq:  INVITE service at 192.168.200.3:5060
>> tid=4b941154408e538aae1822d1ee5fa4ed cseq=INVITE
>> contact=sipp at 217.159.142.96:5061 / 1 from(tu)
>> --------------------------- mMsgToRetransmit END
>> ---------------------------------
>> sbcd: TransactionState.cxx:799: void
>> resip::TransactionState::processClientInvite(resip::TransactionMessage*): 
>>
>> Assertion `mMsgToRetransmit->method() == ACK' failed.
>>
>>
>>
>> To conclusion I have a list of servers (Server1 ... ServerN) and the 
>> proxy
>> should send the received invite to Server1 if the server returns 500 
>> the the
>> proxy should send the same INVITE to Server2 and so on, until the 
>> proxy gets
>> a 200 from ServerX.
>>
>>
>> Am I doing something wrong? Or how can I send the same message to 
>> another
>> ServerX if the Server1 responded with 500.
>>
>>
>> Janari Põld
>>
>> _______________________________________________
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>> resiprocate-devel at list.resiprocate.org
>> https://list.resiprocate.org/mailman/listinfo/resiprocate-devel
>