Osmocom New Splits stacks (osmo-bsc, osmo-msc, osmo-mgw) for voice is SOLVED and stable with LimeSDR-USB!
Voice is working actually since back then, my fault is using only Motorolla C117/118 phone for test call all the time before. (dont use those phone)
Now I just test using newer phone both Caller and Callee for voice is work perfectly!
I tested both osmo-trx-lms and osmo-trx legacy.
using osmo-trx legacy 0.20 also have better performance using the firmware/gateware version I mention here : firmware/gateware version: LimeSDR-USB_HW_1.3_r3.0.img and LimeSDR-USB_HW_1.4_r2.9.rbf from LimeSuite 17.09.0.
The Legacy osmo-nitb also work great!
Noted: using latest osmo-trx-lms great (with downgrading the firmware I mention above and never get error)