Clarification Sieble - AIA

Dears,

Sieble interacts with AIA in a RODOD implementation. example two PIPs are as below

1) sieble - aia - osm

2) sieble - aia - brm

would you be able to point out what are the out of box interface technologies used

meaning to say , what is in between siebel and aia and what siebel component takes care of the interaction (EAI, etc )

I believe there are 2 OOB interaction technologies used betwen siebel and aia.

1) webservice

2) Message queues

3) if any thing else?

so, which component in sieble take care of this interactions and what specific sub-component it would use?

and if you can let me know what order types use what type of interaction , it help further.