When A-MSISDN is
configured to enable this functionality, then the MME will advertise support
for A-MSISDN in S6a ULR messages by setting bit 31 in the Feature List Id 1
AVP. Upon receiving s6a ULA/IDR messages from the HSS, the MME will
- store received A-MSISDN value from the
Subscription Data AVP in the UE context.
- use A-MSISDN as
C-MSISDN in "SRVCC PS to CS Request" and "Forward Relocation Request" messages.
- store received
C-MSISDN as A-MSISDN in the UE context.
Support for A-MSISDN
functionality enables the MME to use the A-MSISDN as a Correlation MSISDN
(C-MSISDN) during SRVCC PS-to-CS handovers. For information on the purpose of
the C-MSISDN, refer to 3GPP TS 23.003.
If the MME sends an
A-MSISDN flag in the ULR, then the MME
- can receive only
one or both MSISDN and A-MSISDN in ULA/IDR messages.
- can send MSISDN
or A-MSISDN as C-MSISDN.
The MME's A-MSISDN
functionality is applicable for ULR/ULA, IDR/IDA, and DSR/DSA command pairs
sent over S6a interface.
The MME also
supports the A-MSISDN withdrawal bit received in DSR Flags AVP. Receipt of this
bit triggers the MME to delete an A-MSISDN from the UE context.