You need to have knowledge on IP Protocols. Know how to network. Know how to present yourself well, and establish eye contact with the interviewer. you will be interviewed once by HR, once by the technical manager and once by the Project Manager or Team Leader of the Team. they will assess your technical skill set. but it doesnt mean that you will fail when you dont know much. personality is still the key . because skill sets can be taught. but attitude is what defines you.