You will need
  • - knowledge of ethical standards and corporate standards.
In some companies it is customary to introduce themselves by name when answering incoming calls. This usually applies to the employees of the call centers, support services and other service structures. But most often it is enough to mention the name of the firm or subdivision.

Corporate standard client-oriented companies often makes the obligatory questions, "how can I help you?", "how can I help?" and the like. Again, this applies, first and foremost, in service units.
If the customer called you, you owe him to introduce myself. You must announce the name of the company, the rest of the set of identifiers (name and surname, position and other, for example, camera number), depending on the user's corporate or personal discretion.
When a call comes from you, ask whether it is convenient for the client to speak. If not, arrange to call at a more convenient time.

The essence of the case setting forth briefly and clearly, ask questions, make suggestions. Listen carefully to the answers.

At the end of the conversation to apologize to me, if your offer to the customer is not approached. Agree on collaboration in positive developments. In any case, thank the interviewee for taking time for you.
If you answer the call, listen carefully to what he wants. Decide the issue on their own, if he's in your jurisdiction, or forward it.
If the client is rude, offends, threatens, that is no reason to answer him in the same coin. His behavior makes it worse, not you. But the company can always use it against him in the case of conflict. Your weapon is politeness and equanimity. By the way, this applies not only to business negotiations.