Hi All,
As per my knowledge, there are 04 types of Call Forwarding for voice calls:
1/CFU (Unconditional)
2/CFNRy (if No Reply)
3/CFBusy (if Busy)
4/CFNRc (if not Reachable)
Is it possible to identify clearly which of them is Early CF and which one is Late CF?
it seems difficult
After many researches, let me answer to myself:
Early Call Forwarding : The MSRN (Mobile Subscriber Roaming Number) is not provided, the HLR/HSS is aware that a Call forward must be triggered, and it provides the Forward-to-Number (C-Number) directly.
Late Call Forwarding: The HLR/HSS is not aware that a Call forward should be triggered, a MSRN is given, the call is extended, the Forward-to-number (C-number) is provided later on.
Thus:
CFU: Early CF
CFNRy: Late CF
CFBusy: Late CF
CFNRc: Early CF
Hi,
Early Call forwarding : (Includes Switch off, Not Reachable & Unconditional)
Late Call forwarding : ( Includes No-answer & Busy )
Early Call Forward : This case usually occurs when B-Party is Out of Coverage area (or) Switched off (or) Uncoditional.
While SRI is triggered to the B-Party HLR , HLR responds with the FTN (Forward to number) with Call forwarding Uncoditional Number or Voice mail depo number as C-Number in SRI_Resp.
Late Call Forward: While SRI is triggered to the B party HLR, HLR responds with the MSRN number in SRI_RESP and the A-party serving MSC will send an ISUP IAM to the corresponding B-party MSC/VLR.
When there is no answer/Busy event received from B-party, the Forward-to-number (C-number) is provided later on.
Hope it is clear..
Recent comments