Code Policy alwasy check O1 mline against Top A1 mline ?

Hi fellows,

I hope everybody are fine.

I would like to know if you have any better idea to try implement the following codec policy in the SBC.

Imagine that I have the following case:

Client A send Initial INVITE with codec PCMU

Then O0= PCMU

Ingress policy

allow-codecs                            PCMU

add-codecs-on-egress PCMU

O1=PCMU

+++

Then in Client B, in the egress policy I have all the codecs.

Egress policy

allow-codecs                            PCMU PCMA G729

add-codecs-on-egress PCMU PCMA G729

Then O2= PCMU PCMA G729

Then from my understanding here the egress policy will work to send(or define) the codecs in the SDP of the initial INVITE (O2) and when the 200OK come from the Client B, then the egress policy will do the same with 20OK SDP (A1).