What are the drawbacks if we use precondition?

Hello all.

I have one question related to VoLTE.

What are the drawbacks if we use precondition?

The advantage would be a shorter call setup time but what will be the possible disadvantages?

What does preconditions means exactly here?

I think reserving resources before alerting to reduce failure is precondition in VoLTE.

Basically PRACK messages exchanged

This is when precondition is ON, when PRACK messages are seen.

More details about precondition are here: Dedicated Bearer setup in LTE and impact on VoLTE Precondition – APT

Precondition tries to make sure that the resources are available end to end before the call is established.

Hence the drawback to go without Preconditioning would be a case where you may hear a ring but the call may not establish because b-party was unavailable actually.

Thanks, but sorry…

My question was what are the drawbacks to use precondition? Any disadvantage? is it a CSCF feature to purchase?

Ah. Sorry.

Preconditioning support is needed on Core. (So may be comercials involved).

Also device manufacturers do the certification for Volte with specific parameters and this may be a concern if you want to change.

I cannot think of something more. Maybe someone else can add to this.

Thank you!