At the user-visible level (advanced settings menus on phones,
GSM 07.05 AT commands, SIM programming) each SMSC is identified
by a numeric address that looks like a phone number, originally
meant to be a Global Title. OsmoMSC passes these SMSC addresses
through as-is to MO-forwardSM.req GSUP message - however, SMSCs
that connect to OsmoHLR via GSUP identify themselves by their
IPA names instead. Hence we need a mapping mechanism in OsmoHLR
config.
To accommodate different styles of network design ranging from
strict recreation of classic GSM architecture to guest roaming
arrangements, a two-level configuration is implemented, modeled
after EUSE/USSD configuration: first one defines which SMSCs exist
as entities, identified only by their IPA names, and then one
defines which numeric SMSC address (in SM-RP-DA) should go to which
configured SMSC, with the additional possibility of a default route.
Related: OS#6135
Change-Id: I1624dcd9d22b4efca965ccdd1c74f0063a94a33c
ff7c7ea085