as I am a production engineer, in a field of engineering technical support job is not like a calling job. both are major differences. for a calling job you don't need a wide knowledge of products and process of engineering you just need good communication skills and basic knowledge of products and their firms and most important convincing skill but as a technical support team member, you need a wide knowledge of products and its design, the process of manufacturing, a calling job is an indoor job while in a tech support job you need to visit working sites