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Double InitialDP message received by SCP

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hoangsonk49
Double InitialDP message received by SCP

Hi all,
I'm using Camel to monitor the network by checking the InitialDp. When a call is set up, the calling number and called number would be logged. Most of them are fine but in some cases, I see a very strange situation: When A calls B, I see in the log 2 messages:
1. Calling number: A ---> Called Party Number:B
2. Calling number:A ---> Called Party BCD Number:B

As I understand, the first mess means the MT call (because the field of CalledPartyBCD is null and CalledPartyNumber is B), and the second means the MO call (because the field of CalledPartyBCD is B and CalledPartyNumber is null). But in fact, ONLY 1 call is set up (A called B) but how I can received 2 InitialDp mess. So, please, with your experience, could you please help me to explain:

1. Is it possible to have 2 InitialDp (one for MT, one for MO as shown) of ONLY 1 call setup?
2. In that case, how can we ignore one of them ?

Thank you very much,

rajesh.k2000
Hello

Hello,
I think if A and B both belongs to ur operator the this is the case.

Thanks

hoangsonk49
Hello

Hi, I don't think so. MO or MT, it depends on which MSC that SCP is connected to, no matter what operator. Even A and B are different operator, we always has calling and called. If SCP is connected to MSC of calling, it considers initialDP as MO, and if SCP is connected to MSC of called, initialDP should be MT. In this case, I'm thinking about A and B belong to the same MSC but with some experiments, I know that in that case, InitialDP is always MO, so it means there is only one InitialDP. From this point, getting a double InitialDP is very strange to me. Please tell me your idea, thanks.

rajesh.k2000
Hello

My thinking is following.

A and b belongs to same operator.
When A calls , B , the serving MSC of A send an IDP to the SCP for MO Call.
When Call reaches to GMSC , then GSMC fo SRI towards HLR and gets TCSI
GSMC sends IDP to the SCP, for MT call towards the B.

So thats why there are two IDPs , and you can see that one is for MO and other is for MT and both have called party number of B.
Thanks