comparison doc/Arch-design @ 6:acc5b1c3e07d default tip

doc/Arch-design: document Osmocom network interface plan
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 23 Dec 2023 08:07:33 +0000
parents 8a7eb3d4570a
children
comparison
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5:8a7eb3d4570a 6:acc5b1c3e07d
824 back home into coverage zone before the received SM expires, they will also 824 back home into coverage zone before the received SM expires, they will also
825 receive the same SM on their GSM phone. 825 receive the same SM on their GSM phone.
826 826
827 4. Interface to local Osmocom GSM network 827 4. Interface to local Osmocom GSM network
828 828
829 GSUP and separate MSISDN-to-IMSI lookup, to be described. 829 There will be two long-lived daemon processes in ThemWi-SMSC dedicated to
830 interfacing with the local Osmocom GSM network:
831
832 * themwi-smsc-gsmif will be the main SMSC-to-GSM interface. It will connect to
833 OsmoHLR via GSUP, and it will appear to the Osmocom network as the SMSC,
834 hiding the other components of ThemWi-SMSC from Osmocom network perspective.
835 This process will be responsible for receiving MO SMs from GSM subscribers
836 and submitting them to themwi-smsc-core, and it will also be responsible for
837 delivering MT SMs to GSM MS once the destination IMSI is known. It will
838 register with themwi-smsc-core as the role-handler for ROLE_GSM_MT_DELIVERY.
839
840 * themwi-smsc-mtimsi will be a much simpler daemon process whose only job will
841 be resolving MSISDNs to IMSIs for MT SMs. It will register with
842 themwi-smsc-core as the role-handler for ROLE_IMSI_LOOKUP.
843
844 In the current (end of 2023) state of Osmocom CNI, there is no way to perform
845 an MSISDN-to-IMSI lookup via GSUP. It is furthermore not obvious how to add
846 such capability, and it is not certain if anyone in Osmocom community (other
847 than us) even cares about the problem of interfacing external SMSCs via GSUP
848 and the associated problem of addressing in the MT direction:
849
850 https://osmocom.org/issues/6312
851
852 Given this uncertainty and lack of interest from other stakeholders, we shall
853 use a not-pretty but very workable solution: themwi-smsc-mtimsi will connect to
854 the CTRL interface of OsmoHLR (as opposed to GSUP) and make queries for
855 subscriber.by-msisdn-XXXX.imsi - a query-able object that was just recently
856 added as a band-aid solution for the current problem.
830 857
831 5. SMPP connection handlers and outside-world SM exchange 858 5. SMPP connection handlers and outside-world SM exchange
832 859
833 To be filled. 860 To be filled.