Sessions between LU 6.2 session partners are used by transaction programs that operate in each partner LU to perform data exchange. Rather than sessions, the basic communication link between logical units using LU 6.2 protocols is a conversation. A conversation is the exclusive use of a session between two partner LUs for some unit of work. Sessions between LU 6.2 session partners are serially reusable. When one conversation ends, another conversation can use that same session between the partner LUs.