It is critical that you know your CV, dates, companies, duties, teams. You will be asked about your previous work experience, so be prepared to answer those questions. The interviewer will expect you to provide him/her with an accurate description of your work experience in a structured way.
When you are doing an interview, you should be focused on that interview. Don’t answer phone calls (yes, some candidates take another call during their telephone interview… And put the interviewer on hold!) Unless it is an emergency, it should be your priority, or at least you should show that you are very interested in the role. Don’t be distracted.
Normally you will be invited to ask questions at the end of the interview. This is as important as answering questions. Think carefully about what you’d like to know about the company or about the position. This is probably much more important than you realize as this will show, firstly, if you have listened to what the interviewer has told you during the interview and secondly, if you have prepared for the interview beforehand.