Greetings from Telecom Tigers Blogspot team!!!!
Here we have tried to explain MNP call flow (Prepaid).
Terms which are used in explanation are already discussed earlier posts.
So let us begin with action.
Assumptions: A and B both are Vodafone Delhi Subscriber in different MSC/MSS coverage area.Let us discuss call flow step by step.
1) Subscriber A (prepaid) call B.
2) Since A is prepaid first query(IDP) has to go IN/SCP with "calling party number" Subscriber A MSISDN and "called party Subscriber" Subscriber B MSISDN. Here is change from normal prepaid call flow, in normal case IDP would have gone straight to serving SCP but in case of MNP IDP will sent to MNP server.
3) MNP server will check its database for B MSISDN and add LRN/RN according to operator to which B subscriber is registered, in above case it is Vodafone Delhi.
After addition of LRN/RN IDP is forwarded to SCP.
4) IDP received by SCP contains LRN/RN + B MSISDN in "called party number" field and "calling party field" contains A MSISDN. Charging is done on the basis of LRN/RN. Here LRN is of Vodafone Delhi so local call rates apply to this call. In normal scenario charging would have be done on the basis on B party MSISDN.
In response to IDP SCP revert with Connect/Continue message to MSC which contains "called party number" as LRN+B MSISDN.
5) MSC check called party number and removes LRN (as its own LRN) and forward SRI to MNP server.
Hereafter normal MNP call flow is followed which is already discussed in detail in earlier post.
6) MNP server checks B MSISDN and forward SRI to HLR.
7) HLR queries with MSC B and provide MSRN to MSC A
8) IAM is send out to MSC B with called number at B party MSRN.
Thereafter normal terminating call flow taken place.
In this post we have given emphasis on changes in prepaid leg for MNP implementation.
Hope it had been informative for you. More call flows to come in case of MNP till then happy reading.
For further queries feel free to revert to undersigned.
CheeeRs!!!
telecomtigers@gmail.com
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Call flow posted on the request of mah friend Mr Robert Sackey
ReplyDeleteCheerS!!!
Shobhit
Hi
ReplyDeleteis it possible to bar prepaid calls before IDP(IinitailDP) to SCP so as to avoid some levels not to be routed to SCP what can be done from MSC side..??.
Hi Hameed,
ReplyDeleteIt is certainly possible to restrict few level prepaid calls before IDP on basis of Subscriber category from MSC.
But it depends on system and configuration done to segregate prepaid and post paid subscribers
Feel free to revert for further queries.....
CHeeeeRs!!!
Thanks for your answer...
ReplyDeleteHi, this is a nice source of information.
ReplyDeleteTwo questions though:
1. Can an MNP query be just for the purpose of MNP query, that is not forwarded to som other network entity, rather it's response is just sent back to the source entity.
Let me elaborate it using the following flow:
MSC_A--(SRI/IDP)-->STP(MNP)--(SRI/IDP+RN)-->HLR/SCP--(SRI/IDP_Resp)-->STP--(SRI/IDP_Resp)-->MSC_A
In the above case, SRI and IDP messages ared estined for HLR and SCP respectively, so they are forwarded accordingly.
My question is explained below:
MSC_A--(MNP_Qry_Msg)-->STP(MNP)--(MNP_Qry_Rsp)--> MSC_A
2. The above scenario/flow discussed by you is for B-party. What about A-party? If I want to charge B-party (lets say he is roaming and i want to charge him for his call, based on the operator of A-party). Can that be incorporated in the normal flow (i mean just for the MNP part) ?
Hi, MNP is Just a Database which is Incorporated in STP.So all the Messages which are going for Query of MNP sever will be very much Destined to STP as Source Elements cant talk to MNP DB directly..
ReplyDeleteif B party is also prepaid he is in roming then how charging will be done.which msc will initiate IDP for B party.as originating msc doe'nt no B party GCI.
ReplyDelete