1.GMSC->MNP-SRF(Unknown subscriber)->GMSC->HLR 2.GMSC->MNP-SRF->HLR ??

[qazmlp]

I'm ambiguous about the handling in the MNP-SRF for the SRI message destined for the non ported-out subscribers.
I could see the following 2 different/mutually exclusive options for this:
a) MNP-SRF reporting 'Unknown subscriber' to the GMSC. GMSC then sends the SRI to the HLR in the same network.
b) MNP-SRF finds that the subscriber does not exist in the NPDB. Then it forwards the SRI to the HLR in the same network. HLR then responds back to the GMSC.

Which one is correct? If both are correct and used in 2 different scenarios, please provide more details about it.

[RussCrush]

Qazlmp

The only scenario I am familiar with is B.

 The NPDB is queried, and the number returned from that query is either the number itself (Not Ported) or an LRN (Ported). The message is then routed on the response.

 My understanding is if the GMSC returns an "Unknown Sub", this is a valid response, and the dialogue will conclude with a failure.

 Does that help?

RussCrush

[qazmlp]

Sorry, your response(B, further discussion seem to be pointing at A) is slightly ambiguous for me.
Do you mean the MNP-SRF should forward the SRI to the HLR in case of the queries for the non ported-out/Home PLMN subscribers(and it is the HLR responsibility to send the SRI response back to the GMSC)?

[RussCrush]

Sorry, I blew it. Let me try again.

 When the SRI for number 5555 gets to the network, it gets dipped to the NPDB. The response is either 5555 (The same number queried) it goes to the HLR, and is processed normally. If the number IS ported, the NPDB response contains 6666 (Local Routing Number) and a point code, and the message replaces the CalledPartyAddress with the LRN, and routes it out of the network based on either the LRN or the point code. If the GMSC has a route for the point code, that comes first, if not, it goes SCCP.

 Scenario A is not used, I think because if the SRI goes to the HLR first, the Unknown sub is a valid response from the HLR, and the dialogue fails. I have not seen it used anywhere.