I am very clear when come to LI and KU business partner because it is straight forward, but I am confused of
1 - when do we need to create a LS partner?
2 - Does LS partner is a MUST step if I want to communicate with my external vendor/customer (these will be created with LI and KU)? in another word, if I want to use IDOC transaction with my business partner. I think not require right? because I can use LI and KU right away?