Where I work (brief esse about my job)

I work in the IT-sphere. I work in a company which is systems integrator company. Our company is not big. There are about two hundred workers. Systems integration is not the only thing the company does, but it's a very important aspect of the company.  Beside that, our company provides different products and services, such as retail computers and accessories, retail software, computer repair, and so on.
So, what is systems integration? What does that mean?  Systems integration is the development a full-services systems for a company.  Among these services are included network infrastructure with integrated telephony services (VoIP, PSTN), and telepresence systems (videoconferencing), data-centers (sometimes with a cloud computing service, virtualization, and so on).  Thus, we offer to our clients servers, network equipment, and different software, such as workflow systems. We also have a software development department and web development department.
I'm a systems engineer. I specialize in security: network security, information security, security of personal data, and so on. I develop security systems for different purposes. In my work I often use different types of equipment from various vendors, such as Cisco, Juniper and others. I have to know how the networks are work according to a seven-layered model OSI and according to different standards, RFCs and best-practices.