When does an assignment start

Prior to the first meeting, I had a mundane and briefing talk with the client about various things, they asking me questions about business usage and the importance of this or that company. We were still 30 minutes away from the meeting time but the assignment for me was already on air. Trying and answer meaningfully to their questions was, is part of my job, because clients also judge the quality of the business liaison interpreter by knowledgeable answers to their concerns. Language competence of the Japanese we were about to meet was also a big issue. They had no clue. I offered them to clarify this subject right away after we exchange business cards. After the exchange, I quickly took a smily, lenient attitude to ask them about their English competence and how we could efficiently proceed: everything in Japanese or only Q & A. One of the objective in this first cordial contact managed by the interpreter after agreement with the client, is to grease the wheel of communication, what with a case where the interpreter is not a Japanese national like myself. There is no definitive answer to whether this introduction can be waved or not, but I have the feeling that it works at reassuring the Japanese side tat everything will be fine. When the real interpreting session begins, it is nothing but the second stage of a play that already started at least an hour ago. Do they teach you issues of interaction with clients and that other side at interpretation schools?