Attention is currently required from: falconia, fixeria, neels.
nt2mku has posted comments on this change. ( https://gerrit.osmocom.org/c/libosmocore/+/36784?usp=email )
Change subject: gsm48_encode_bearer_cap(): omit octet 3a if only GSM-FR/GSM-HR v1 is supported ......................................................................
Patch Set 7:
(1 comment)
Patchset:
PS7:
I always thought that including the Bearer Capability IE in MO SETUP for a voice call allows to ne […]
So I've just tested to completely omit the Bearer Capability IE in outgoing MT setup and it looks good with Phase 1 & Phase 2 GSM, and a Smartphone so far.
Osmo-MSC: `src/libmsc/gsm_04_08_cc.c` function `gsm48_cc_tx_setup()` Added: `if(trans->bearer_cap.transfer != GSM48_BCAP_ITCAP_SPEECH)` `gsm48_encode_bearer_cap(msg, 0, &bearer_cap);`
The codec negotiation still succeeds, the logging shows in case of smartphone to phase 1 GSM call: `<0001> msc_a.c:2086 trans(CC:INITIATED ... :CM_SERVICE_REQ ... codecs: ... MS={AMR:octet-align=1#112,GSM-EFR#110,GSM-HR-08#111,GSM#3} bss={GSM#3,GSM-EFR#110,AMR:octet-align=1#112} RAN={AMR:octet-align=1#112,GSM-EFR#110,GSM#3,GSM-HR-08#111})`
`<0001> gsm_04_08_cc.c:1186 trans(CC:CALL_RECEIVED ... :PAGING_RESP ... codecs: ... MS={GSM#3} bss={GSM#3,GSM-EFR#110,AMR:octet-align=1#112} RAN={AMR:octet-align=1#112,GSM-EFR#110,GSM#3,GSM-HR-08#111})`