EDI 856 question

Can we use EDI 856 for both inbound and out bound.

Case: we create a delivery in SAP and send Delivery Detail via EDI 856 out bound to a logistics service provider for further processing of the delivery (Picking and Packing).

If there is any change to the same delivery at logistic service provider ex: if there is change in the actual quantity packed, can the Logistics service provider sends those details back via same interface EDI 856 inbound to SAP.

What are the technical things we need to make sure to map this process.