VoLTE user stuck in 2G in good LTE radio conditions

Hi Experts.

Any idea why VoLTE user stuck in 2G in good LTE radio conditions?

1 Like

Could be anything ranging from TAU reject in LTE to no EARFCN info in SI2Q 2G.

1 Like

What should I need to check?

Majorly this happening on other MNC number.

1 Like

Check SIB2Quatr in 2G whether it has EARFCN info.

Check NAS if there was any undesired TAU rejects or EMM rejects like #15 or #19.

1 Like

Yes undesired reject was there.

1 Like

Then you have the reason :+1:t2:

1 Like

But I didn’t find when customer goes to 2G why it doesn’t come back to LTE.

Why it needs to fresh LU.